RE: Exercise can add years to life

[Guest guest]

>>How's four more years sound to you, Rodney?

Its not quite four " more " years.

It found that if you exercise you dont die as " soon " as those who didnt exercise

from CVD.

So, you get four " more " years than the " shortened " lifespan of the typical

sedentary unhealthy American, but you dont really " extend " your life.

Maybe semantics again.

Jeff'

[Guest guest]

>>How's four more years sound to you, Rodney?

Its not quite four " more " years.

It found that if you exercise you dont die as " soon " as those who didnt exercise

from CVD.

So, you get four " more " years than the " shortened " lifespan of the typical

sedentary unhealthy American, but you dont really " extend " your life.

Maybe semantics again.

Jeff'

[Guest guest]

Hi Diane:

Thanks Diane. Four more years sounds excellent for your typical over

weight/obese, artery clogged, smoking, 300 total

cholesterol, 'accident sitting on the edge of its chair itching for

an opportunity to happen' north american.

By far the largest cause of death is, of course, CVD. Most of it in

people such as those described above. For them, I have no doubt,

exercise helps. So would drinking a couple of glasses of wine a day -

indeed, imo, it would likely help more than the exercise. And of

course, to one degree or other the vast majority fall into the

category described above. Thirty-three percent are obese; sixty-six

percent are over weight or obese. And these numbers are calculated

in relation to the undoubtedly too high reference standards currently

in 'conventional-wisdom' use to describe an 'OK' BMI. I.E. that

anything below a BMI of 26 is fabulous, and below 30 is pretty good.

And because so many people are over weight inevitably it is the

members of the study samples with those characteristics that are

responsible for the study results.

[As I have said many times before. It is high time people stopped

using your average fat american as their study control groups. We

all know they are unhealthy. We and they all know what they should

be doing to fix their problem. We all know that a CRON approach is

much healthier. So I believe that if we want to progress, studies

should now start to use CRON subjects as the control group].

However, in the case of exercise (as has similarly been argued here

for wine consumption) what evidence do we have that people who: have

a CR BMI, or something approaching it; check to make sure they do not

have key nutrient deficiencies; eat predominantly the foods that

everyone who can read knows are healthy; who do not have high lipids

values or any other indications of CVD susceptibility; will gain

anywhere remotely to the same extent as those with a BMI of 30,

etc.? Indeed, is there evidence that CRers will benefit at all from

large amounts of exercise? We will never know until someone does a

study with a CRON control group.

My impression is that the benefits of exercise observed for your

typical north american are overwhelmingly the result of a delay in

onset of CVD, and a delay in death from CVD. If the CVD risk factor

values of those who are established at a CRON weight (WUSTL) mean

anything then there is no chance they will succumb to CVD and will

achieve **zero** CVD benefits from exercise. So I am interested in

studies which show other life-saving benefits from exercise.

(Incidentally, in the Copenhagen study I have posted here more than

once, it was found that wine drinking dramatically reduced mortality

from **all** causes separately, not just CVD)

We all agree, I think, (and yes, that includes me as well as our good

old Dr. Henry ) that a certain modest-to-moderate degree of

exercise is absolutely essential for health. The issue, imo, is

whether, and if so how much, benefit intrinsically very healthy

people can derive from going beyond that threshold ......... while

burning extra calories to do it.

I have yet to see evidence suggesting exercise in amounts beyond that

threshold will benefit CRers. That doesn't necessarily mean it

doesn't exist. If it does exist I would certainly like to see it. I

would also like to see evidence that indicates approximately where

that threshold resides. According to Dr. , the threshold is

at a very low level.

Rodney.

>

> How's four more years sound to you, Rodney?

>

> http://tinyurl.com/cm3d7

>

>

> Effects of Physical Activity on Life Expectancy With Cardiovascular

> Disease

>

> H. Franco, MD, PhD; de Laet, MD, PhD; Peeters, PhD;

> Jonker, MSc; Johan Mackenbach, MD, PhD; Wilma Nusselder,

PhD

>

> Arch Intern Med. 2005;165:2355-2360.

>

> Diane

>

[Guest guest]

Hi Diane:

Thanks Diane. Four more years sounds excellent for your typical over

weight/obese, artery clogged, smoking, 300 total

cholesterol, 'accident sitting on the edge of its chair itching for

an opportunity to happen' north american.

By far the largest cause of death is, of course, CVD. Most of it in

people such as those described above. For them, I have no doubt,

exercise helps. So would drinking a couple of glasses of wine a day -

indeed, imo, it would likely help more than the exercise. And of

course, to one degree or other the vast majority fall into the

category described above. Thirty-three percent are obese; sixty-six

percent are over weight or obese. And these numbers are calculated

in relation to the undoubtedly too high reference standards currently

in 'conventional-wisdom' use to describe an 'OK' BMI. I.E. that

anything below a BMI of 26 is fabulous, and below 30 is pretty good.

And because so many people are over weight inevitably it is the

members of the study samples with those characteristics that are

responsible for the study results.

[As I have said many times before. It is high time people stopped

using your average fat american as their study control groups. We

all know they are unhealthy. We and they all know what they should

be doing to fix their problem. We all know that a CRON approach is

much healthier. So I believe that if we want to progress, studies

should now start to use CRON subjects as the control group].

However, in the case of exercise (as has similarly been argued here

for wine consumption) what evidence do we have that people who: have

a CR BMI, or something approaching it; check to make sure they do not

have key nutrient deficiencies; eat predominantly the foods that

everyone who can read knows are healthy; who do not have high lipids

values or any other indications of CVD susceptibility; will gain

anywhere remotely to the same extent as those with a BMI of 30,

etc.? Indeed, is there evidence that CRers will benefit at all from

large amounts of exercise? We will never know until someone does a

study with a CRON control group.

My impression is that the benefits of exercise observed for your

typical north american are overwhelmingly the result of a delay in

onset of CVD, and a delay in death from CVD. If the CVD risk factor

values of those who are established at a CRON weight (WUSTL) mean

anything then there is no chance they will succumb to CVD and will

achieve **zero** CVD benefits from exercise. So I am interested in

studies which show other life-saving benefits from exercise.

(Incidentally, in the Copenhagen study I have posted here more than

once, it was found that wine drinking dramatically reduced mortality

from **all** causes separately, not just CVD)

We all agree, I think, (and yes, that includes me as well as our good

old Dr. Henry ) that a certain modest-to-moderate degree of

exercise is absolutely essential for health. The issue, imo, is

whether, and if so how much, benefit intrinsically very healthy

people can derive from going beyond that threshold ......... while

burning extra calories to do it.

I have yet to see evidence suggesting exercise in amounts beyond that

threshold will benefit CRers. That doesn't necessarily mean it

doesn't exist. If it does exist I would certainly like to see it. I

would also like to see evidence that indicates approximately where

that threshold resides. According to Dr. , the threshold is

at a very low level.

Rodney.

>

> How's four more years sound to you, Rodney?

>

> http://tinyurl.com/cm3d7

>

>

> Effects of Physical Activity on Life Expectancy With Cardiovascular

> Disease

>

> H. Franco, MD, PhD; de Laet, MD, PhD; Peeters, PhD;

> Jonker, MSc; Johan Mackenbach, MD, PhD; Wilma Nusselder,

PhD

>

> Arch Intern Med. 2005;165:2355-2360.

>

> Diane

>

[Guest guest]

--- Diane Walter <dianepwalter@...> wrote:

> How's four more years sound to you, Rodney?

>

> http://tinyurl.com/cm3d7

The whole story, All, is:

In This Issue of Archives of Internal Medicine

Arch Intern Med. 2005;165:2319.

Prescribing Exercise at Varied Levels of Intensity and Frequency

This randomized trial examined the effects of counseling free-living, sedentary

adults to exercise at different levels of intensity and frequency. Significant

improvements in cardiorespiratory fitness were achieved and maintained over 24

months via exercise counseling with a prescription for walking 30 minutes per

day,

either at a moderate intensity 5 to 7 days per week or at a hard intensity 3 to

4

days per week. Additional benefits, including larger changes in fitness level

and

short-term increases in high-density lipoprotein cholesterol level, were

achieved by

prescribing the combination of hard-intensity plus high-frequency exercise.

Editorials

How Much and What Type of Physical Activity Is Enough?: What Physicians Should

Tell

Their Patients

N. Blair; J. LaMonte

Arch Intern Med. 2005;165:2324-2325.

Regular physical activity is associated with higher levels of physical fitness,

particularly aerobic power or cardiorespiratory fitness, favorable

chronic-disease

risk-factor profiles, reduced risk of clinical events, and greater longevity.1-4

However, an incomplete understanding still exists as to the specific dose of

physical activity, in terms of frequency, intensity, and duration, and the

related

volume of energy expenditure that is effective in achieving specific biological

or

clinical outcomes.

The report by Duncan et al5 in this issue of the ARCHIVES provides important new

information on patterns of exercise intensity and frequency in relation to

changes

in cardiorespiratory fitness and cardiovascular disease (CVD) risk factors. In

this

well-designed and well-conducted study, the investigators assigned participants

to

physician-assisted counseling (the comparison group) or to 1 of 4 intervention

groups composed of 2 exercise intensities (45%-55% or 65%-75% of maximal heart

rate

---

reserve) and 2 exercise frequencies (3-4 sessions/wk or 5-7 sessions/wk).

Exercise intensity was objectively monitored using an electronic HR recording

device. Walking was the exercise modality, the duration of which was constant

(30

min/d) for all intervention groups. Primary outcomes were changes in

cardiorespiratory fitness (quantified as maximal oxygen uptake in milliliters

per

kilogram per minute) and changes in selected CVD risk factors at 6 and 24 months

after baseline. The intervention groups received intensive behavioral counseling

based on methods of demonstrated effectiveness in previous exercise intervention

trials. The investigators achieved acceptable adherence to the interventions and

to

follow-up examinations.

We comment here primarily on the changes observed in cardiorespiratory fitness,

which is a strong predictor of numerous health outcomes, including morbidity and

mortality,6-7 and is perhaps the best indicator of response to aerobic exercise

training. As illustrated in the Figure in the article by Duncan et al,5

high-intensity exercise (at either low or high frequency) and moderate-intensity

activity at high frequency show significant and similar increases in fitness

over

baseline at 24 months. Participants in the moderate-intensity activity at low

frequency and physician-assisted counseling groups had nonsignificant fitness

increases of about 1% over baseline.

Public health recommendations for physical activity1-4 vary slightly in the

several

published reports, but the consensus is that the frequency should be 5 d/wk or

more

of moderate-intensity physical activity for 30 min/d or a frequency of 3 d/wk or

more at vigorous intensity for 20 min/d. Definitions are different in the

various

reports, but moderate intensity is typically defined as an absolute intensity of

3

to 6 metabolic equivalents (METs), and vigorous intensity as more than 6 METs.

Recommendations for moderate-intensity activity lead to total exercise doses

ranging

from 7.5 to 15.0 MET h/wk.

Duncan et al5 prescribed intensity on the basis of HR reserve, which is a

relative

intensity and is influenced by age, health status, fitness level, and activity

pattern. The percentage of HR reserve is roughly comparable to the percentage of

maximal METs; and the maximal METs, as calculated from the maximal oxygen uptake

values reported in Table 1 in their article, were approximately 6.6 METs in

women

and 8.5 METs in men. These data yield total exercise dose targets ranging from

around 4.5 MET h/wk (about 338 kcal/wk for a 75-kg person) to as much as 22.3

MET

h/wk (about 1673 kcal/wk for a 75-kg person), with the lowest value being the

approximate dose for women in the moderate-intensity, low-frequency group and

the

highest value being for men in the high-intensity, high-frequency group. The

total

volume of exercise actually completed by study participants was 58% to 66% of

the

prescribed dose, or ranging from 3.6 MET h/wk for the moderate-intensity,

low-frequency group to 6.8 MET h/wk for the high-intensity, high frequency

group.

All doses of at least 4 MET h/wk, or about 300 kcal/wk for a 75-kg person

(moderate-intensity, high-frequency group), showed significant increases in

fitness

over baseline. Thus, a dose of 4 MET h/wk appears to be beneficial, even though

this

amount of weekly energy expenditure is a bit lower than the consensus

recommendation. Furthermore, individuals in the moderate-intensity,

high-frequency

group achieved similar improvements in cardiorespiratory fitness to those in

either

of the high-intensity groups.

Although these observations must be generalized with caution, they carry

important

public health and clinical implications. Because the exercise modality was

walking,

which is the most prevalent form of physical activity reported by US adults,1

the

findings should be encouraging for health care providers who counsel individuals

on

increasing their physical activity habits. Practitioners should begin by

presenting

the consensus public health recommendation to their patients, with the goal of

increasing activity levels to 30 minutes of moderate-intensity walking 5 d/wk or

more. Practitioners can routinely encourage their patients to strive for this

dose,

but they can expect that in some individuals, fitness and health benefits may

occur

even if they do not attain it on a regular basis. The results reported by Duncan

et

al5 indicate that health benefits may be achieved by some individuals at the

relatively low dose of 4 MET h/wk (about 300 kcal for a 75-kg person). These

findings should be generalized with caution until additional randomized

controlled

trials are undertaken to confirm the observations.

Other results of the study are worth noting. There was no significant difference

for

adherence between the low- and high-frequency groups, suggesting that

recommending 5

to 7 d/wk of exercise is not a deterrent. The finding that participants in

moderate-intensity groups had a significantly better adherence (66%) than did

participants in the high-intensity groups (58%) reinforces the notion that

moderate-intensity physical activity may be more acceptable than strenuous

physical

activities, particularly for initially sedentary or physically inactive adults

such

as those enrolled in this study.

Duncan et al5 found that only the high-intensity, high-frequency group showed

significant improvements in high-density lipoprotein cholesterol levels and in

the

total cholesterol/high-density lipoprotein cholesterol ratio. It may well be

that

higher doses of physical activity are required to affect the lipid profile.

However,

with the exception of being physically inactive and overweight, the average

baseline

risk factor profile among the middle-aged study participants was clinically

normal.

As indicated by the authors, persons with abnormal lipid levels were excluded

from

the study, so it is possible that the exercise doses achieved by these

participants

might have had some effect on those with abnormal lipid levels.

Nonetheless, it is important to note that the health benefits of physical

activity

and cardiorespiratory fitness extend beyond any effect they might have on

conventional chronic disease risk factors. Our research group has shown

substantial

benefits of moderate levels of cardiorespiratory fitness in relation to CVD or

all-cause mortality, independent of age, sex, and conventional CVD risk

factors.6

Moderate fitness also was associated with lower mortality risk in numerous

subgroups

of our population, including those who were obese and men with hypertension,

diabetes, or metabolic syndrome.7-10 In fact, our data suggest that being

physically

active and fit may be of particular importance for those who have already

expressed

clinically relevant risk factor levels or chronic disease.7-8 Thus it is

important

for practitioners and their patients to not judge the health benefits of regular

physical activity solely by its effect on conventional risk factors; they should

counsel their patients that regular activity is beneficial whether or not it

improves their lipid profile, blood pressure, weight, or glucose tolerance.

In summary, Duncan et al5 have demonstrated that various combinations of

exercise

frequency and intensity, yielding a modest total physical activity dose, can be

effective in increasing aerobic power. Individuals who choose to exercise at a

higher intensity (65%-75% of maximal HR reserve) can make significant

improvements

in their fitness by walking for 30 minutes 3 or 4 d/wk. Likewise, persons who

prefer

a lower intensity of 45% to 55% can obtain similar benefits by walking for 30

minutes 5 to 7 d/wk. The findings reported by Duncan et al are further evidence

of

the opportunity that practitioners have in counseling their patients on a health

behavior that has critical importance for primary and secondary disease

prevention.

Our current work on topics relevant to this editorial is supported in part by

equipment grants from Life Fitness, Schiller Park, Ill

Effects of Physical Activity on Life Expectancy With Cardiovascular Disease

H. Franco; de Laet; Peeters; Jonker; Johan

Mackenbach;

Wilma Nusselder

Arch Intern Med. 2005;165:2355-2360.

ABSTRACT

Background Physical inactivity is a modifiable risk factor for cardiovascular

disease. However, little is known about the effects of physical activity on life

expectancy with and without cardiovascular disease. Our objective was to

calculate

the consequences of different physical activity levels after age 50 years on

total

life expectancy and life expectancy with and without cardiovascular disease.

Methods We constructed multistate life tables using data from the Framingham

Heart

Study to calculate the effects of 3 levels of physical activity (low, moderate,

and

high) among populations older than 50 years. For the life table calculations, we

used hazard ratios for 3 transitions (healthy to death, healthy to disease, and

disease to death) by levels of physical activity and adjusted for age, sex,

smoking,

any comorbidity (cancer, left ventricular hypertrophy, arthritis, diabetes,

ankle

edema, or pulmonary disease), and examination at start of follow-up period.

Results Moderate and high physical activity levels led to 1.3 and 3.7 years

more in

total life expectancy and 1.1 and 3.2 more years lived without cardiovascular

disease, respectively, for men aged 50 years or older compared with those who

maintained a low physical activity level. For women the differences were 1.5 and

3.5

years in total life expectancy and 1.3 and 3.3 more years lived free of

cardiovascular disease, respectively.

Conclusions Avoiding a sedentary lifestyle during adulthood not only prevents

cardiovascular disease independently of other risk factors but also

substantially

expands the total life expectancy and the cardiovascular disease–free life

expectancy for men and women. This effect is already seen at moderate levels of

physical activity, and the gains in cardiovascular disease–free life expectancy

are

twice as large at higher activity levels.

Prescribing Exercise at Varied Levels of Intensity and Frequency: A Randomized

Trial

Glen E. Duncan; D. Anton; Sumner J. Sydeman; L. Newton Jr; Joyce

A.

Corsica; E. Durning; U. Ketterson; A. ; n C.

Limacher; G. Perri

Arch Intern Med. 2005;165:2362-2369.

ABSTRACT

Background Regular physical activity produces beneficial effects on health, but

the

exercise prescription needed to improve cardiovascular disease risk factors in

free-living sedentary individuals remains unclear.

Methods Sedentary adults (N = 492, 64.0% women) were randomized to 1 of 4

exercise-counseling conditions or to a physician advice comparison group. The

duration (30 minutes) and type (walking) of exercise were held constant, while

exercise intensity and frequency were manipulated to form 4 exercise

prescriptions:

moderate intensity–low frequency, moderate intensity–high frequency (HiF), hard

intensity (HardI)–low frequency, and HardI-HiF. Comparison group participants

received physician advice and written materials regarding recommended levels of

exercise for health. Outcomes included 6- and 24-month changes in

cardiorespiratory

fitness (maximum oxygen consumption), high-density lipoprotein cholesterol

(HDL-C)

level, and the total cholesterol–HDL-C ratio.

Results At 6 months, the HardI-HiF, HardI–low-frequency, and

moderate-intensity–HiF

conditions demonstrated significant increases in maximum oxygen consumption

(P<.01

for all), but only the HardI-HiF condition showed significant improvements in

HDL-C

level (P<.03), total cholesterol–HDL-C ratio (P<.04), and maximum oxygen

consumption

(P<.01) compared with physician advice. At 24 months, the increases in maximum

oxygen consumption remained significantly higher than baseline in the HardI-HiF,

HardI–low-frequency, and moderate-intensity–HiF conditions and in the HardI-HiF

group compared with physician advice (P<.01 for all), but no significant effects

on

HDL-C level (P = .57) or total cholesterol–HDL-C ratio (P = .64) were observed.

Conclusions Exercise counseling with a prescription for walking at either a

HardI

or a HiF produced significant long-term improvements in cardiorespiratory

fitness.

More exercise or the combination of HardI plus HiF exercise may provide

additional

benefits, including larger fitness changes and improved lipid profiles.

.... Table 2. Observed Values for Cardiorespiratory Fitness and for Lipoproteins

and

Lipids at Baseline and Change From Baseline to 6 Months by Condition

==========================

----Condition*

Variable----HardI-HiF (n = 86) ModI-HiF (n = 94) HardI-LowF (n = 80) ModI-LowF

(n =

73) PA (n = 78)

==========================

V^O2Max, L/min

Baseline 2.09±0.69 2.04±0.59 2.03±0.58 2.20±0.60 2.00±0.55

Change 0.15±0.24†‡¶ 0.08±0.15† 0.07±0.18† 0.02±0.15 0.04±0.22

TC, mg/dL

Baseline 193.4±37.7 192.5±29.2 189.8±28.6 195.4±27.6 186.5±31.4

Change -1.3±18.0 0.9±15.9 -0.5±16.3 0.4±17.8 -0.3±15.0

LDL-C, mg/dL

Baseline 115.5±28.4 114.3±26.4 114.5±25.9 118.8±25.5 109.3±26.7

Change -2.2±14.4 1.0±14.3 -0.8±13.8 -1.0±14.5 0±13.7

HDL-C, mg/dL

Baseline 52.13±12.21 54.49±14.93 53.47±11.49 54.49±14.93 55.43±13.44

Change 1.83±6.11†‡¶ 0.54±6.43 -0.09±5.55 1.44±6.87 0.03±5.23

TC/HDL-C ratio

Baseline 3.89±1.09 3.78±1.09 3.71±0.95 4.02±1.33 3.55±1.02

Change -0.12±0.33†‡¶ 0.04±0.55 -0.02±0.46 -0.05±0.48 0.02±0.37

TG, mg/dL

Baseline 124.8±74.0 119.0±59.4 108.3±52.5 123.9±70.8 108.9±67.1

Change -6.9±40.7 8.4±46.6 2.4±29.4 -0.2±37.1 -2.1±33.3

==========================

Abbreviations: BMI, body mass index (calculated as weight in kilograms divided

by

the square of height in meters); DBP, diastolic blood pressure; FBG,

fastingblood

glucose; HardI, hard intensity; HDL-C, high-density lipoprotein cholesterol;

HiF,

high frequency; LDL-C, low-density lipoprotein cholesterol; LowF, low frequency;

ModI, moderate intensity; PA, physician advice; SBP, systolic blood pressure;

TC,

total cholesterol; TG, triglycerides; V ÿ O2max, maximum oxygen consumption.

SI conversion factors: To convert FBG to millimoles per liter, multiply by

0.0555;

to convert HDL-C, LDL-C, and TC to millimoles per liter, multiply by 0.0259; and

to

convert TG to millimoles per liter, multiply by 0.0113.

*Data are given as mean±SD. The HardI-HiF, HardI-LowF, and ModI-HiF conditions

demonstrated significant increases in V^O2Max (P<.01), but only the

HardI-HiF condition showed significant improvements in HDL-C level, TC/HDL-C

ratio,

and V^O2Max, compared with the PA and ModI-LowF groups (P<.01 for

each). For more details, see the “Cardiorespiratory Fitness” and “Lipids,

Lipoproteins, and Other Measures” subsections of the “Results” section.

†Significant (P<.01) change from baseline.

‡Significant (P<.01) change compared with the ModI-LowF condition.

¶Significant (P<.01) change compared with the PA condition.

Al Pater, PhD; email: old542000@...

__________________________________

- PC Magazine Editors' Choice 2005

http://mail.

[Guest guest]

--- Diane Walter <dianepwalter@...> wrote:

> How's four more years sound to you, Rodney?

>

> http://tinyurl.com/cm3d7

The whole story, All, is:

In This Issue of Archives of Internal Medicine

Arch Intern Med. 2005;165:2319.

Prescribing Exercise at Varied Levels of Intensity and Frequency

This randomized trial examined the effects of counseling free-living, sedentary

adults to exercise at different levels of intensity and frequency. Significant

improvements in cardiorespiratory fitness were achieved and maintained over 24

months via exercise counseling with a prescription for walking 30 minutes per

day,

either at a moderate intensity 5 to 7 days per week or at a hard intensity 3 to

4

days per week. Additional benefits, including larger changes in fitness level

and

short-term increases in high-density lipoprotein cholesterol level, were

achieved by

prescribing the combination of hard-intensity plus high-frequency exercise.

Editorials

How Much and What Type of Physical Activity Is Enough?: What Physicians Should

Tell

Their Patients

N. Blair; J. LaMonte

Arch Intern Med. 2005;165:2324-2325.

Regular physical activity is associated with higher levels of physical fitness,

particularly aerobic power or cardiorespiratory fitness, favorable

chronic-disease

risk-factor profiles, reduced risk of clinical events, and greater longevity.1-4

However, an incomplete understanding still exists as to the specific dose of

physical activity, in terms of frequency, intensity, and duration, and the

related

volume of energy expenditure that is effective in achieving specific biological

or

clinical outcomes.

The report by Duncan et al5 in this issue of the ARCHIVES provides important new

information on patterns of exercise intensity and frequency in relation to

changes

in cardiorespiratory fitness and cardiovascular disease (CVD) risk factors. In

this

well-designed and well-conducted study, the investigators assigned participants

to

physician-assisted counseling (the comparison group) or to 1 of 4 intervention

groups composed of 2 exercise intensities (45%-55% or 65%-75% of maximal heart

rate

---

reserve) and 2 exercise frequencies (3-4 sessions/wk or 5-7 sessions/wk).

Exercise intensity was objectively monitored using an electronic HR recording

device. Walking was the exercise modality, the duration of which was constant

(30

min/d) for all intervention groups. Primary outcomes were changes in

cardiorespiratory fitness (quantified as maximal oxygen uptake in milliliters

per

kilogram per minute) and changes in selected CVD risk factors at 6 and 24 months

after baseline. The intervention groups received intensive behavioral counseling

based on methods of demonstrated effectiveness in previous exercise intervention

trials. The investigators achieved acceptable adherence to the interventions and

to

follow-up examinations.

We comment here primarily on the changes observed in cardiorespiratory fitness,

which is a strong predictor of numerous health outcomes, including morbidity and

mortality,6-7 and is perhaps the best indicator of response to aerobic exercise

training. As illustrated in the Figure in the article by Duncan et al,5

high-intensity exercise (at either low or high frequency) and moderate-intensity

activity at high frequency show significant and similar increases in fitness

over

baseline at 24 months. Participants in the moderate-intensity activity at low

frequency and physician-assisted counseling groups had nonsignificant fitness

increases of about 1% over baseline.

Public health recommendations for physical activity1-4 vary slightly in the

several

published reports, but the consensus is that the frequency should be 5 d/wk or

more

of moderate-intensity physical activity for 30 min/d or a frequency of 3 d/wk or

more at vigorous intensity for 20 min/d. Definitions are different in the

various

reports, but moderate intensity is typically defined as an absolute intensity of

3

to 6 metabolic equivalents (METs), and vigorous intensity as more than 6 METs.

Recommendations for moderate-intensity activity lead to total exercise doses

ranging

from 7.5 to 15.0 MET h/wk.

Duncan et al5 prescribed intensity on the basis of HR reserve, which is a

relative

intensity and is influenced by age, health status, fitness level, and activity

pattern. The percentage of HR reserve is roughly comparable to the percentage of

maximal METs; and the maximal METs, as calculated from the maximal oxygen uptake

values reported in Table 1 in their article, were approximately 6.6 METs in

women

and 8.5 METs in men. These data yield total exercise dose targets ranging from

around 4.5 MET h/wk (about 338 kcal/wk for a 75-kg person) to as much as 22.3

MET

h/wk (about 1673 kcal/wk for a 75-kg person), with the lowest value being the

approximate dose for women in the moderate-intensity, low-frequency group and

the

highest value being for men in the high-intensity, high-frequency group. The

total

volume of exercise actually completed by study participants was 58% to 66% of

the

prescribed dose, or ranging from 3.6 MET h/wk for the moderate-intensity,

low-frequency group to 6.8 MET h/wk for the high-intensity, high frequency

group.

All doses of at least 4 MET h/wk, or about 300 kcal/wk for a 75-kg person

(moderate-intensity, high-frequency group), showed significant increases in

fitness

over baseline. Thus, a dose of 4 MET h/wk appears to be beneficial, even though

this

amount of weekly energy expenditure is a bit lower than the consensus

recommendation. Furthermore, individuals in the moderate-intensity,

high-frequency

group achieved similar improvements in cardiorespiratory fitness to those in

either

of the high-intensity groups.

Although these observations must be generalized with caution, they carry

important

public health and clinical implications. Because the exercise modality was

walking,

which is the most prevalent form of physical activity reported by US adults,1

the

findings should be encouraging for health care providers who counsel individuals

on

increasing their physical activity habits. Practitioners should begin by

presenting

the consensus public health recommendation to their patients, with the goal of

increasing activity levels to 30 minutes of moderate-intensity walking 5 d/wk or

more. Practitioners can routinely encourage their patients to strive for this

dose,

but they can expect that in some individuals, fitness and health benefits may

occur

even if they do not attain it on a regular basis. The results reported by Duncan

et

al5 indicate that health benefits may be achieved by some individuals at the

relatively low dose of 4 MET h/wk (about 300 kcal for a 75-kg person). These

findings should be generalized with caution until additional randomized

controlled

trials are undertaken to confirm the observations.

Other results of the study are worth noting. There was no significant difference

for

adherence between the low- and high-frequency groups, suggesting that

recommending 5

to 7 d/wk of exercise is not a deterrent. The finding that participants in

moderate-intensity groups had a significantly better adherence (66%) than did

participants in the high-intensity groups (58%) reinforces the notion that

moderate-intensity physical activity may be more acceptable than strenuous

physical

activities, particularly for initially sedentary or physically inactive adults

such

as those enrolled in this study.

Duncan et al5 found that only the high-intensity, high-frequency group showed

significant improvements in high-density lipoprotein cholesterol levels and in

the

total cholesterol/high-density lipoprotein cholesterol ratio. It may well be

that

higher doses of physical activity are required to affect the lipid profile.

However,

with the exception of being physically inactive and overweight, the average

baseline

risk factor profile among the middle-aged study participants was clinically

normal.

As indicated by the authors, persons with abnormal lipid levels were excluded

from

the study, so it is possible that the exercise doses achieved by these

participants

might have had some effect on those with abnormal lipid levels.

Nonetheless, it is important to note that the health benefits of physical

activity

and cardiorespiratory fitness extend beyond any effect they might have on

conventional chronic disease risk factors. Our research group has shown

substantial

benefits of moderate levels of cardiorespiratory fitness in relation to CVD or

all-cause mortality, independent of age, sex, and conventional CVD risk

factors.6

Moderate fitness also was associated with lower mortality risk in numerous

subgroups

of our population, including those who were obese and men with hypertension,

diabetes, or metabolic syndrome.7-10 In fact, our data suggest that being

physically

active and fit may be of particular importance for those who have already

expressed

clinically relevant risk factor levels or chronic disease.7-8 Thus it is

important

for practitioners and their patients to not judge the health benefits of regular

physical activity solely by its effect on conventional risk factors; they should

counsel their patients that regular activity is beneficial whether or not it

improves their lipid profile, blood pressure, weight, or glucose tolerance.

In summary, Duncan et al5 have demonstrated that various combinations of

exercise

frequency and intensity, yielding a modest total physical activity dose, can be

effective in increasing aerobic power. Individuals who choose to exercise at a

higher intensity (65%-75% of maximal HR reserve) can make significant

improvements

in their fitness by walking for 30 minutes 3 or 4 d/wk. Likewise, persons who

prefer

a lower intensity of 45% to 55% can obtain similar benefits by walking for 30

minutes 5 to 7 d/wk. The findings reported by Duncan et al are further evidence

of

the opportunity that practitioners have in counseling their patients on a health

behavior that has critical importance for primary and secondary disease

prevention.

Our current work on topics relevant to this editorial is supported in part by

equipment grants from Life Fitness, Schiller Park, Ill

Effects of Physical Activity on Life Expectancy With Cardiovascular Disease

H. Franco; de Laet; Peeters; Jonker; Johan

Mackenbach;

Wilma Nusselder

Arch Intern Med. 2005;165:2355-2360.

ABSTRACT

Background Physical inactivity is a modifiable risk factor for cardiovascular

disease. However, little is known about the effects of physical activity on life

expectancy with and without cardiovascular disease. Our objective was to

calculate

the consequences of different physical activity levels after age 50 years on

total

life expectancy and life expectancy with and without cardiovascular disease.

Methods We constructed multistate life tables using data from the Framingham

Heart

Study to calculate the effects of 3 levels of physical activity (low, moderate,

and

high) among populations older than 50 years. For the life table calculations, we

used hazard ratios for 3 transitions (healthy to death, healthy to disease, and

disease to death) by levels of physical activity and adjusted for age, sex,

smoking,

any comorbidity (cancer, left ventricular hypertrophy, arthritis, diabetes,

ankle

edema, or pulmonary disease), and examination at start of follow-up period.

Results Moderate and high physical activity levels led to 1.3 and 3.7 years

more in

total life expectancy and 1.1 and 3.2 more years lived without cardiovascular

disease, respectively, for men aged 50 years or older compared with those who

maintained a low physical activity level. For women the differences were 1.5 and

3.5

years in total life expectancy and 1.3 and 3.3 more years lived free of

cardiovascular disease, respectively.

Conclusions Avoiding a sedentary lifestyle during adulthood not only prevents

cardiovascular disease independently of other risk factors but also

substantially

expands the total life expectancy and the cardiovascular disease–free life

expectancy for men and women. This effect is already seen at moderate levels of

physical activity, and the gains in cardiovascular disease–free life expectancy

are

twice as large at higher activity levels.

Prescribing Exercise at Varied Levels of Intensity and Frequency: A Randomized

Trial

Glen E. Duncan; D. Anton; Sumner J. Sydeman; L. Newton Jr; Joyce

A.

Corsica; E. Durning; U. Ketterson; A. ; n C.

Limacher; G. Perri

Arch Intern Med. 2005;165:2362-2369.

ABSTRACT

Background Regular physical activity produces beneficial effects on health, but

the

exercise prescription needed to improve cardiovascular disease risk factors in

free-living sedentary individuals remains unclear.

Methods Sedentary adults (N = 492, 64.0% women) were randomized to 1 of 4

exercise-counseling conditions or to a physician advice comparison group. The

duration (30 minutes) and type (walking) of exercise were held constant, while

exercise intensity and frequency were manipulated to form 4 exercise

prescriptions:

moderate intensity–low frequency, moderate intensity–high frequency (HiF), hard

intensity (HardI)–low frequency, and HardI-HiF. Comparison group participants

received physician advice and written materials regarding recommended levels of

exercise for health. Outcomes included 6- and 24-month changes in

cardiorespiratory

fitness (maximum oxygen consumption), high-density lipoprotein cholesterol

(HDL-C)

level, and the total cholesterol–HDL-C ratio.

Results At 6 months, the HardI-HiF, HardI–low-frequency, and

moderate-intensity–HiF

conditions demonstrated significant increases in maximum oxygen consumption

(P<.01

for all), but only the HardI-HiF condition showed significant improvements in

HDL-C

level (P<.03), total cholesterol–HDL-C ratio (P<.04), and maximum oxygen

consumption

(P<.01) compared with physician advice. At 24 months, the increases in maximum

oxygen consumption remained significantly higher than baseline in the HardI-HiF,

HardI–low-frequency, and moderate-intensity–HiF conditions and in the HardI-HiF

group compared with physician advice (P<.01 for all), but no significant effects

on

HDL-C level (P = .57) or total cholesterol–HDL-C ratio (P = .64) were observed.

Conclusions Exercise counseling with a prescription for walking at either a

HardI

or a HiF produced significant long-term improvements in cardiorespiratory

fitness.

More exercise or the combination of HardI plus HiF exercise may provide

additional

benefits, including larger fitness changes and improved lipid profiles.

.... Table 2. Observed Values for Cardiorespiratory Fitness and for Lipoproteins

and

Lipids at Baseline and Change From Baseline to 6 Months by Condition

==========================

----Condition*

Variable----HardI-HiF (n = 86) ModI-HiF (n = 94) HardI-LowF (n = 80) ModI-LowF

(n =

73) PA (n = 78)

==========================

V^O2Max, L/min

Baseline 2.09±0.69 2.04±0.59 2.03±0.58 2.20±0.60 2.00±0.55

Change 0.15±0.24†‡¶ 0.08±0.15† 0.07±0.18† 0.02±0.15 0.04±0.22

TC, mg/dL

Baseline 193.4±37.7 192.5±29.2 189.8±28.6 195.4±27.6 186.5±31.4

Change -1.3±18.0 0.9±15.9 -0.5±16.3 0.4±17.8 -0.3±15.0

LDL-C, mg/dL

Baseline 115.5±28.4 114.3±26.4 114.5±25.9 118.8±25.5 109.3±26.7

Change -2.2±14.4 1.0±14.3 -0.8±13.8 -1.0±14.5 0±13.7

HDL-C, mg/dL

Baseline 52.13±12.21 54.49±14.93 53.47±11.49 54.49±14.93 55.43±13.44

Change 1.83±6.11†‡¶ 0.54±6.43 -0.09±5.55 1.44±6.87 0.03±5.23

TC/HDL-C ratio

Baseline 3.89±1.09 3.78±1.09 3.71±0.95 4.02±1.33 3.55±1.02

Change -0.12±0.33†‡¶ 0.04±0.55 -0.02±0.46 -0.05±0.48 0.02±0.37

TG, mg/dL

Baseline 124.8±74.0 119.0±59.4 108.3±52.5 123.9±70.8 108.9±67.1

Change -6.9±40.7 8.4±46.6 2.4±29.4 -0.2±37.1 -2.1±33.3

==========================

Abbreviations: BMI, body mass index (calculated as weight in kilograms divided

by

the square of height in meters); DBP, diastolic blood pressure; FBG,

fastingblood

glucose; HardI, hard intensity; HDL-C, high-density lipoprotein cholesterol;

HiF,

high frequency; LDL-C, low-density lipoprotein cholesterol; LowF, low frequency;

ModI, moderate intensity; PA, physician advice; SBP, systolic blood pressure;

TC,

total cholesterol; TG, triglycerides; V ÿ O2max, maximum oxygen consumption.

SI conversion factors: To convert FBG to millimoles per liter, multiply by

0.0555;

to convert HDL-C, LDL-C, and TC to millimoles per liter, multiply by 0.0259; and

to

convert TG to millimoles per liter, multiply by 0.0113.

*Data are given as mean±SD. The HardI-HiF, HardI-LowF, and ModI-HiF conditions

demonstrated significant increases in V^O2Max (P<.01), but only the

HardI-HiF condition showed significant improvements in HDL-C level, TC/HDL-C

ratio,

and V^O2Max, compared with the PA and ModI-LowF groups (P<.01 for

each). For more details, see the “Cardiorespiratory Fitness” and “Lipids,

Lipoproteins, and Other Measures” subsections of the “Results” section.

†Significant (P<.01) change from baseline.

‡Significant (P<.01) change compared with the ModI-LowF condition.

¶Significant (P<.01) change compared with the PA condition.

Al Pater, PhD; email: old542000@...

__________________________________

- PC Magazine Editors' Choice 2005

http://mail.

[Guest guest]

"Conclusions Avoiding a sedentary lifestyle during adulthood not only preventscardiovascular disease independently of other risk factors but also substantiallyexpands the total life expectancy and the cardiovascular disease–free lifeexpectancy for men and women. This effect is already seen at moderate levels ofphysical activity, and the gains in cardiovascular disease–free life expectancy aretwice as large at higher activity levels. "

Isn't it odd that it does not prevent CVD in a 20 yo footballer, that died in his dorm?

I seriously question the word "prevents". How about all the guys who do a lot of real physical labor - why do they get CVD? What's the diff between working a fishing boat to exhaustion in Finland and running 20 miles per day?

If the statement were true, a great many athletes (that have been athletes for a long time) would be greater in number.

I would see an article that says 80% of all 80 - 100 yos are athletes.

Regards.

Re: [ ] Exercise can add years to life

--- Diane Walter <dianepwalter@...> wrote:> How's four more years sound to you, Rodney?> > http://tinyurl.com/cm3d7The whole story, All, is:In This Issue of Archives of Internal Medicine Arch Intern Med. 2005;165:2319. Prescribing Exercise at Varied Levels of Intensity and Frequency This randomized trial examined the effects of counseling free-living, sedentaryadults to exercise at different levels of intensity and frequency. Significantimprovements in cardiorespiratory fitness were achieved and maintained over 24months via exercise counseling with a prescription for walking 30 minutes per day,either at a moderate intensity 5 to 7 days per week or at a hard intensity 3 to 4days per week. Additional benefits, including larger changes in fitness level andshort-term increases in high-density lipoprotein cholesterol level, were achieved byprescribing the combination of hard-intensity plus high-frequency exercise.Editorials How Much and What Type of Physical Activity Is Enough?: What Physicians Should TellTheir Patients N. Blair; J. LaMonteArch Intern Med. 2005;165:2324-2325.Regular physical activity is associated with higher levels of physical fitness,particularly aerobic power or cardiorespiratory fitness, favorable chronic-diseaserisk-factor profiles, reduced risk of clinical events, and greater longevity.1-4However, an incomplete understanding still exists as to the specific dose ofphysical activity, in terms of frequency, intensity, and duration, and the relatedvolume of energy expenditure that is effective in achieving specific biological orclinical outcomes. The report by Duncan et al5 in this issue of the ARCHIVES provides important newinformation on patterns of exercise intensity and frequency in relation to changesin cardiorespiratory fitness and cardiovascular disease (CVD) risk factors. In thiswell-designed and well-conducted study, the investigators assigned participants tophysician-assisted counseling (the comparison group) or to 1 of 4 interventiongroups composed of 2 exercise intensities (45%-55% or 65%-75% of maximal heart rate

---

reserve) and 2 exercise frequencies (3-4 sessions/wk or 5-7 sessions/wk).Exercise intensity was objectively monitored using an electronic HR recordingdevice. Walking was the exercise modality, the duration of which was constant (30min/d) for all intervention groups. Primary outcomes were changes incardiorespiratory fitness (quantified as maximal oxygen uptake in milliliters perkilogram per minute) and changes in selected CVD risk factors at 6 and 24 monthsafter baseline. The intervention groups received intensive behavioral counselingbased on methods of demonstrated effectiveness in previous exercise interventiontrials. The investigators achieved acceptable adherence to the interventions and tofollow-up examinations. We comment here primarily on the changes observed in cardiorespiratory fitness,which is a strong predictor of numerous health outcomes, including morbidity andmortality,6-7 and is perhaps the best indicator of response to aerobic exercisetraining. As illustrated in the Figure in the article by Duncan et al,5high-intensity exercise (at either low or high frequency) and moderate-intensityactivity at high frequency show significant and similar increases in fitness overbaseline at 24 months. Participants in the moderate-intensity activity at lowfrequency and physician-assisted counseling groups had nonsignificant fitnessincreases of about 1% over baseline. Public health recommendations for physical activity1-4 vary slightly in the severalpublished reports, but the consensus is that the frequency should be 5 d/wk or moreof moderate-intensity physical activity for 30 min/d or a frequency of 3 d/wk ormore at vigorous intensity for 20 min/d. Definitions are different in the variousreports, but moderate intensity is typically defined as an absolute intensity of 3to 6 metabolic equivalents (METs), and vigorous intensity as more than 6 METs.Recommendations for moderate-intensity activity lead to total exercise doses rangingfrom 7.5 to 15.0 MET h/wk. Duncan et al5 prescribed intensity on the basis of HR reserve, which is a relativeintensity and is influenced by age, health status, fitness level, and activitypattern. The percentage of HR reserve is roughly comparable to the percentage ofmaximal METs; and the maximal METs, as calculated from the maximal oxygen uptakevalues reported in Table 1 in their article, were approximately 6.6 METs in womenand 8.5 METs in men. These data yield total exercise dose targets ranging fromaround 4.5 MET h/wk (about 338 kcal/wk for a 75-kg person) to as much as 22.3 METh/wk (about 1673 kcal/wk for a 75-kg person), with the lowest value being theapproximate dose for women in the moderate-intensity, low-frequency group and thehighest value being for men in the high-intensity, high-frequency group. The totalvolume of exercise actually completed by study participants was 58% to 66% of theprescribed dose, or ranging from 3.6 MET h/wk for the moderate-intensity,low-frequency group to 6.8 MET h/wk for the high-intensity, high frequency group.All doses of at least 4 MET h/wk, or about 300 kcal/wk for a 75-kg person(moderate-intensity, high-frequency group), showed significant increases in fitnessover baseline. Thus, a dose of 4 MET h/wk appears to be beneficial, even though thisamount of weekly energy expenditure is a bit lower than the consensusrecommendation. Furthermore, individuals in the moderate-intensity, high-frequencygroup achieved similar improvements in cardiorespiratory fitness to those in eitherof the high-intensity groups. Although these observations must be generalized with caution, they carry importantpublic health and clinical implications. Because the exercise modality was walking,which is the most prevalent form of physical activity reported by US adults,1 thefindings should be encouraging for health care providers who counsel individuals onincreasing their physical activity habits. Practitioners should begin by presentingthe consensus public health recommendation to their patients, with the goal ofincreasing activity levels to 30 minutes of moderate-intensity walking 5 d/wk ormore. Practitioners can routinely encourage their patients to strive for this dose,but they can expect that in some individuals, fitness and health benefits may occureven if they do not attain it on a regular basis. The results reported by Duncan etal5 indicate that health benefits may be achieved by some individuals at therelatively low dose of 4 MET h/wk (about 300 kcal for a 75-kg person). Thesefindings should be generalized with caution until additional randomized controlledtrials are undertaken to confirm the observations. Other results of the study are worth noting. There was no significant difference foradherence between the low- and high-frequency groups, suggesting that recommending 5to 7 d/wk of exercise is not a deterrent. The finding that participants inmoderate-intensity groups had a significantly better adherence (66%) than didparticipants in the high-intensity groups (58%) reinforces the notion thatmoderate-intensity physical activity may be more acceptable than strenuous physicalactivities, particularly for initially sedentary or physically inactive adults suchas those enrolled in this study. Duncan et al5 found that only the high-intensity, high-frequency group showedsignificant improvements in high-density lipoprotein cholesterol levels and in thetotal cholesterol/high-density lipoprotein cholesterol ratio. It may well be thathigher doses of physical activity are required to affect the lipid profile. However,with the exception of being physically inactive and overweight, the average baselinerisk factor profile among the middle-aged study participants was clinically normal.As indicated by the authors, persons with abnormal lipid levels were excluded fromthe study, so it is possible that the exercise doses achieved by these participantsmight have had some effect on those with abnormal lipid levels. Nonetheless, it is important to note that the health benefits of physical activityand cardiorespiratory fitness extend beyond any effect they might have onconventional chronic disease risk factors. Our research group has shown substantialbenefits of moderate levels of cardiorespiratory fitness in relation to CVD orall-cause mortality, independent of age, sex, and conventional CVD risk factors.6Moderate fitness also was associated with lower mortality risk in numerous subgroupsof our population, including those who were obese and men with hypertension,diabetes, or metabolic syndrome.7-10 In fact, our data suggest that being physicallyactive and fit may be of particular importance for those who have already expressedclinically relevant risk factor levels or chronic disease.7-8 Thus it is importantfor practitioners and their patients to not judge the health benefits of regularphysical activity solely by its effect on conventional risk factors; they shouldcounsel their patients that regular activity is beneficial whether or not itimproves their lipid profile, blood pressure, weight, or glucose tolerance. In summary, Duncan et al5 have demonstrated that various combinations of exercisefrequency and intensity, yielding a modest total physical activity dose, can beeffective in increasing aerobic power. Individuals who choose to exercise at ahigher intensity (65%-75% of maximal HR reserve) can make significant improvementsin their fitness by walking for 30 minutes 3 or 4 d/wk. Likewise, persons who prefera lower intensity of 45% to 55% can obtain similar benefits by walking for 30minutes 5 to 7 d/wk. The findings reported by Duncan et al are further evidence ofthe opportunity that practitioners have in counseling their patients on a healthbehavior that has critical importance for primary and secondary disease prevention.Our current work on topics relevant to this editorial is supported in part byequipment grants from Life Fitness, Schiller Park, IllEffects of Physical Activity on Life Expectancy With Cardiovascular Disease H. Franco; de Laet; Peeters; Jonker; Johan Mackenbach;Wilma NusselderArch Intern Med. 2005;165:2355-2360.ABSTRACT Background Physical inactivity is a modifiable risk factor for cardiovasculardisease. However, little is known about the effects of physical activity on lifeexpectancy with and without cardiovascular disease. Our objective was to calculatethe consequences of different physical activity levels after age 50 years on totallife expectancy and life expectancy with and without cardiovascular disease. Methods We constructed multistate life tables using data from the Framingham HeartStudy to calculate the effects of 3 levels of physical activity (low, moderate, andhigh) among populations older than 50 years. For the life table calculations, weused hazard ratios for 3 transitions (healthy to death, healthy to disease, anddisease to death) by levels of physical activity and adjusted for age, sex, smoking,any comorbidity (cancer, left ventricular hypertrophy, arthritis, diabetes, ankleedema, or pulmonary disease), and examination at start of follow-up period. Results Moderate and high physical activity levels led to 1.3 and 3.7 years more intotal life expectancy and 1.1 and 3.2 more years lived without cardiovasculardisease, respectively, for men aged 50 years or older compared with those whomaintained a low physical activity level. For women the differences were 1.5 and 3.5years in total life expectancy and 1.3 and 3.3 more years lived free ofcardiovascular disease, respectively. Conclusions Avoiding a sedentary lifestyle during adulthood not only preventscardiovascular disease independently of other risk factors but also substantiallyexpands the total life expectancy and the cardiovascular disease–free lifeexpectancy for men and women. This effect is already seen at moderate levels ofphysical activity, and the gains in cardiovascular disease–free life expectancy aretwice as large at higher activity levels. Prescribing Exercise at Varied Levels of Intensity and Frequency: A Randomized TrialGlen E. Duncan; D. Anton; Sumner J. Sydeman; L. Newton Jr; Joyce A.Corsica; E. Durning; U. Ketterson; A. ; n C.Limacher; G. PerriArch Intern Med. 2005;165:2362-2369.ABSTRACT Background Regular physical activity produces beneficial effects on health, but theexercise prescription needed to improve cardiovascular disease risk factors infree-living sedentary individuals remains unclear. Methods Sedentary adults (N = 492, 64.0% women) were randomized to 1 of 4exercise-counseling conditions or to a physician advice comparison group. Theduration (30 minutes) and type (walking) of exercise were held constant, whileexercise intensity and frequency were manipulated to form 4 exercise prescriptions:moderate intensity–low frequency, moderate intensity–high frequency (HiF), hardintensity (HardI)–low frequency, and HardI-HiF. Comparison group participantsreceived physician advice and written materials regarding recommended levels ofexercise for health. Outcomes included 6- and 24-month changes in cardiorespiratoryfitness (maximum oxygen consumption), high-density lipoprotein cholesterol (HDL-C)level, and the total cholesterol–HDL-C ratio. Results At 6 months, the HardI-HiF, HardI–low-frequency, and moderate-intensity–HiFconditions demonstrated significant increases in maximum oxygen consumption (P<.01for all), but only the HardI-HiF condition showed significant improvements in HDL-Clevel (P<.03), total cholesterol–HDL-C ratio (P<.04), and maximum oxygen consumption(P<.01) compared with physician advice. At 24 months, the increases in maximumoxygen consumption remained significantly higher than baseline in the HardI-HiF,HardI–low-frequency, and moderate-intensity–HiF conditions and in the HardI-HiFgroup compared with physician advice (P<.01 for all), but no significant effects onHDL-C level (P = .57) or total cholesterol–HDL-C ratio (P = .64) were observed. Conclusions Exercise counseling with a prescription for walking at either a HardIor a HiF produced significant long-term improvements in cardiorespiratory fitness.More exercise or the combination of HardI plus HiF exercise may provide additionalbenefits, including larger fitness changes and improved lipid profiles. ... Table 2. Observed Values for Cardiorespiratory Fitness and for Lipoproteins andLipids at Baseline and Change From Baseline to 6 Months by Condition========================== ----Condition*Variable----HardI-HiF (n = 86) ModI-HiF (n = 94) HardI-LowF (n = 80) ModI-LowF (n =73) PA (n = 78)==========================V^O2Max, L/min Baseline 2.09±0.69 2.04±0.59 2.03±0.58 2.20±0.60 2.00±0.55 Change 0.15±0.24†‡¶ 0.08±0.15† 0.07±0.18† 0.02±0.15 0.04±0.22TC, mg/dL Baseline 193.4±37.7 192.5±29.2 189.8±28.6 195.4±27.6 186.5±31.4 Change -1.3±18.0 0.9±15.9 -0.5±16.3 0.4±17.8 -0.3±15.0LDL-C, mg/dL Baseline 115.5±28.4 114.3±26.4 114.5±25.9 118.8±25.5 109.3±26.7 Change -2.2±14.4 1.0±14.3 -0.8±13.8 -1.0±14.5 0±13.7HDL-C, mg/dL Baseline 52.13±12.21 54.49±14.93 53.47±11.49 54.49±14.93 55.43±13.44 Change 1.83±6.11†‡¶ 0.54±6.43 -0.09±5.55 1.44±6.87 0.03±5.23TC/HDL-C ratio Baseline 3.89±1.09 3.78±1.09 3.71±0.95 4.02±1.33 3.55±1.02 Change -0.12±0.33†‡¶ 0.04±0.55 -0.02±0.46 -0.05±0.48 0.02±0.37TG, mg/dL Baseline 124.8±74.0 119.0±59.4 108.3±52.5 123.9±70.8 108.9±67.1 Change -6.9±40.7 8.4±46.6 2.4±29.4 -0.2±37.1 -2.1±33.3==========================Abbreviations: BMI, body mass index (calculated as weight in kilograms divided bythe square of height in meters); DBP, diastolic blood pressure; FBG, fastingbloodglucose; HardI, hard intensity; HDL-C, high-density lipoprotein cholesterol; HiF,high frequency; LDL-C, low-density lipoprotein cholesterol; LowF, low frequency;ModI, moderate intensity; PA, physician advice; SBP, systolic blood pressure; TC,total cholesterol; TG, triglycerides; V ÿ O2max, maximum oxygen consumption.SI conversion factors: To convert FBG to millimoles per liter, multiply by 0.0555;to convert HDL-C, LDL-C, and TC to millimoles per liter, multiply by 0.0259; and toconvert TG to millimoles per liter, multiply by 0.0113.*Data are given as mean±SD. The HardI-HiF, HardI-LowF, and ModI-HiF conditionsdemonstrated significant increases in V^O2Max (P<.01), but only theHardI-HiF condition showed significant improvements in HDL-C level, TC/HDL-C ratio,and V^O2Max, compared with the PA and ModI-LowF groups (P<.01 foreach). For more details, see the “Cardiorespiratory Fitness” and “Lipids,Lipoproteins, and Other Measures” subsections of the “Results” section.†Significant (P<.01) change from baseline.‡Significant (P<.01) change compared with the ModI-LowF condition.¶Significant (P<.01) change compared with the PA condition.Al Pater, PhD; email: old542000@...

[Guest guest]

"Conclusions Avoiding a sedentary lifestyle during adulthood not only preventscardiovascular disease independently of other risk factors but also substantiallyexpands the total life expectancy and the cardiovascular disease–free lifeexpectancy for men and women. This effect is already seen at moderate levels ofphysical activity, and the gains in cardiovascular disease–free life expectancy aretwice as large at higher activity levels. "

Isn't it odd that it does not prevent CVD in a 20 yo footballer, that died in his dorm?

I seriously question the word "prevents". How about all the guys who do a lot of real physical labor - why do they get CVD? What's the diff between working a fishing boat to exhaustion in Finland and running 20 miles per day?

If the statement were true, a great many athletes (that have been athletes for a long time) would be greater in number.

I would see an article that says 80% of all 80 - 100 yos are athletes.

Regards.

Re: [ ] Exercise can add years to life

--- Diane Walter <dianepwalter@...> wrote:> How's four more years sound to you, Rodney?> > http://tinyurl.com/cm3d7The whole story, All, is:In This Issue of Archives of Internal Medicine Arch Intern Med. 2005;165:2319. Prescribing Exercise at Varied Levels of Intensity and Frequency This randomized trial examined the effects of counseling free-living, sedentaryadults to exercise at different levels of intensity and frequency. Significantimprovements in cardiorespiratory fitness were achieved and maintained over 24months via exercise counseling with a prescription for walking 30 minutes per day,either at a moderate intensity 5 to 7 days per week or at a hard intensity 3 to 4days per week. Additional benefits, including larger changes in fitness level andshort-term increases in high-density lipoprotein cholesterol level, were achieved byprescribing the combination of hard-intensity plus high-frequency exercise.Editorials How Much and What Type of Physical Activity Is Enough?: What Physicians Should TellTheir Patients N. Blair; J. LaMonteArch Intern Med. 2005;165:2324-2325.Regular physical activity is associated with higher levels of physical fitness,particularly aerobic power or cardiorespiratory fitness, favorable chronic-diseaserisk-factor profiles, reduced risk of clinical events, and greater longevity.1-4However, an incomplete understanding still exists as to the specific dose ofphysical activity, in terms of frequency, intensity, and duration, and the relatedvolume of energy expenditure that is effective in achieving specific biological orclinical outcomes. The report by Duncan et al5 in this issue of the ARCHIVES provides important newinformation on patterns of exercise intensity and frequency in relation to changesin cardiorespiratory fitness and cardiovascular disease (CVD) risk factors. In thiswell-designed and well-conducted study, the investigators assigned participants tophysician-assisted counseling (the comparison group) or to 1 of 4 interventiongroups composed of 2 exercise intensities (45%-55% or 65%-75% of maximal heart rate

---

reserve) and 2 exercise frequencies (3-4 sessions/wk or 5-7 sessions/wk).Exercise intensity was objectively monitored using an electronic HR recordingdevice. Walking was the exercise modality, the duration of which was constant (30min/d) for all intervention groups. Primary outcomes were changes incardiorespiratory fitness (quantified as maximal oxygen uptake in milliliters perkilogram per minute) and changes in selected CVD risk factors at 6 and 24 monthsafter baseline. The intervention groups received intensive behavioral counselingbased on methods of demonstrated effectiveness in previous exercise interventiontrials. The investigators achieved acceptable adherence to the interventions and tofollow-up examinations. We comment here primarily on the changes observed in cardiorespiratory fitness,which is a strong predictor of numerous health outcomes, including morbidity andmortality,6-7 and is perhaps the best indicator of response to aerobic exercisetraining. As illustrated in the Figure in the article by Duncan et al,5high-intensity exercise (at either low or high frequency) and moderate-intensityactivity at high frequency show significant and similar increases in fitness overbaseline at 24 months. Participants in the moderate-intensity activity at lowfrequency and physician-assisted counseling groups had nonsignificant fitnessincreases of about 1% over baseline. Public health recommendations for physical activity1-4 vary slightly in the severalpublished reports, but the consensus is that the frequency should be 5 d/wk or moreof moderate-intensity physical activity for 30 min/d or a frequency of 3 d/wk ormore at vigorous intensity for 20 min/d. Definitions are different in the variousreports, but moderate intensity is typically defined as an absolute intensity of 3to 6 metabolic equivalents (METs), and vigorous intensity as more than 6 METs.Recommendations for moderate-intensity activity lead to total exercise doses rangingfrom 7.5 to 15.0 MET h/wk. Duncan et al5 prescribed intensity on the basis of HR reserve, which is a relativeintensity and is influenced by age, health status, fitness level, and activitypattern. The percentage of HR reserve is roughly comparable to the percentage ofmaximal METs; and the maximal METs, as calculated from the maximal oxygen uptakevalues reported in Table 1 in their article, were approximately 6.6 METs in womenand 8.5 METs in men. These data yield total exercise dose targets ranging fromaround 4.5 MET h/wk (about 338 kcal/wk for a 75-kg person) to as much as 22.3 METh/wk (about 1673 kcal/wk for a 75-kg person), with the lowest value being theapproximate dose for women in the moderate-intensity, low-frequency group and thehighest value being for men in the high-intensity, high-frequency group. The totalvolume of exercise actually completed by study participants was 58% to 66% of theprescribed dose, or ranging from 3.6 MET h/wk for the moderate-intensity,low-frequency group to 6.8 MET h/wk for the high-intensity, high frequency group.All doses of at least 4 MET h/wk, or about 300 kcal/wk for a 75-kg person(moderate-intensity, high-frequency group), showed significant increases in fitnessover baseline. Thus, a dose of 4 MET h/wk appears to be beneficial, even though thisamount of weekly energy expenditure is a bit lower than the consensusrecommendation. Furthermore, individuals in the moderate-intensity, high-frequencygroup achieved similar improvements in cardiorespiratory fitness to those in eitherof the high-intensity groups. Although these observations must be generalized with caution, they carry importantpublic health and clinical implications. Because the exercise modality was walking,which is the most prevalent form of physical activity reported by US adults,1 thefindings should be encouraging for health care providers who counsel individuals onincreasing their physical activity habits. Practitioners should begin by presentingthe consensus public health recommendation to their patients, with the goal ofincreasing activity levels to 30 minutes of moderate-intensity walking 5 d/wk ormore. Practitioners can routinely encourage their patients to strive for this dose,but they can expect that in some individuals, fitness and health benefits may occureven if they do not attain it on a regular basis. The results reported by Duncan etal5 indicate that health benefits may be achieved by some individuals at therelatively low dose of 4 MET h/wk (about 300 kcal for a 75-kg person). Thesefindings should be generalized with caution until additional randomized controlledtrials are undertaken to confirm the observations. Other results of the study are worth noting. There was no significant difference foradherence between the low- and high-frequency groups, suggesting that recommending 5to 7 d/wk of exercise is not a deterrent. The finding that participants inmoderate-intensity groups had a significantly better adherence (66%) than didparticipants in the high-intensity groups (58%) reinforces the notion thatmoderate-intensity physical activity may be more acceptable than strenuous physicalactivities, particularly for initially sedentary or physically inactive adults suchas those enrolled in this study. Duncan et al5 found that only the high-intensity, high-frequency group showedsignificant improvements in high-density lipoprotein cholesterol levels and in thetotal cholesterol/high-density lipoprotein cholesterol ratio. It may well be thathigher doses of physical activity are required to affect the lipid profile. However,with the exception of being physically inactive and overweight, the average baselinerisk factor profile among the middle-aged study participants was clinically normal.As indicated by the authors, persons with abnormal lipid levels were excluded fromthe study, so it is possible that the exercise doses achieved by these participantsmight have had some effect on those with abnormal lipid levels. Nonetheless, it is important to note that the health benefits of physical activityand cardiorespiratory fitness extend beyond any effect they might have onconventional chronic disease risk factors. Our research group has shown substantialbenefits of moderate levels of cardiorespiratory fitness in relation to CVD orall-cause mortality, independent of age, sex, and conventional CVD risk factors.6Moderate fitness also was associated with lower mortality risk in numerous subgroupsof our population, including those who were obese and men with hypertension,diabetes, or metabolic syndrome.7-10 In fact, our data suggest that being physicallyactive and fit may be of particular importance for those who have already expressedclinically relevant risk factor levels or chronic disease.7-8 Thus it is importantfor practitioners and their patients to not judge the health benefits of regularphysical activity solely by its effect on conventional risk factors; they shouldcounsel their patients that regular activity is beneficial whether or not itimproves their lipid profile, blood pressure, weight, or glucose tolerance. In summary, Duncan et al5 have demonstrated that various combinations of exercisefrequency and intensity, yielding a modest total physical activity dose, can beeffective in increasing aerobic power. Individuals who choose to exercise at ahigher intensity (65%-75% of maximal HR reserve) can make significant improvementsin their fitness by walking for 30 minutes 3 or 4 d/wk. Likewise, persons who prefera lower intensity of 45% to 55% can obtain similar benefits by walking for 30minutes 5 to 7 d/wk. The findings reported by Duncan et al are further evidence ofthe opportunity that practitioners have in counseling their patients on a healthbehavior that has critical importance for primary and secondary disease prevention.Our current work on topics relevant to this editorial is supported in part byequipment grants from Life Fitness, Schiller Park, IllEffects of Physical Activity on Life Expectancy With Cardiovascular Disease H. Franco; de Laet; Peeters; Jonker; Johan Mackenbach;Wilma NusselderArch Intern Med. 2005;165:2355-2360.ABSTRACT Background Physical inactivity is a modifiable risk factor for cardiovasculardisease. However, little is known about the effects of physical activity on lifeexpectancy with and without cardiovascular disease. Our objective was to calculatethe consequences of different physical activity levels after age 50 years on totallife expectancy and life expectancy with and without cardiovascular disease. Methods We constructed multistate life tables using data from the Framingham HeartStudy to calculate the effects of 3 levels of physical activity (low, moderate, andhigh) among populations older than 50 years. For the life table calculations, weused hazard ratios for 3 transitions (healthy to death, healthy to disease, anddisease to death) by levels of physical activity and adjusted for age, sex, smoking,any comorbidity (cancer, left ventricular hypertrophy, arthritis, diabetes, ankleedema, or pulmonary disease), and examination at start of follow-up period. Results Moderate and high physical activity levels led to 1.3 and 3.7 years more intotal life expectancy and 1.1 and 3.2 more years lived without cardiovasculardisease, respectively, for men aged 50 years or older compared with those whomaintained a low physical activity level. For women the differences were 1.5 and 3.5years in total life expectancy and 1.3 and 3.3 more years lived free ofcardiovascular disease, respectively. Conclusions Avoiding a sedentary lifestyle during adulthood not only preventscardiovascular disease independently of other risk factors but also substantiallyexpands the total life expectancy and the cardiovascular disease–free lifeexpectancy for men and women. This effect is already seen at moderate levels ofphysical activity, and the gains in cardiovascular disease–free life expectancy aretwice as large at higher activity levels. Prescribing Exercise at Varied Levels of Intensity and Frequency: A Randomized TrialGlen E. Duncan; D. Anton; Sumner J. Sydeman; L. Newton Jr; Joyce A.Corsica; E. Durning; U. Ketterson; A. ; n C.Limacher; G. PerriArch Intern Med. 2005;165:2362-2369.ABSTRACT Background Regular physical activity produces beneficial effects on health, but theexercise prescription needed to improve cardiovascular disease risk factors infree-living sedentary individuals remains unclear. Methods Sedentary adults (N = 492, 64.0% women) were randomized to 1 of 4exercise-counseling conditions or to a physician advice comparison group. Theduration (30 minutes) and type (walking) of exercise were held constant, whileexercise intensity and frequency were manipulated to form 4 exercise prescriptions:moderate intensity–low frequency, moderate intensity–high frequency (HiF), hardintensity (HardI)–low frequency, and HardI-HiF. Comparison group participantsreceived physician advice and written materials regarding recommended levels ofexercise for health. Outcomes included 6- and 24-month changes in cardiorespiratoryfitness (maximum oxygen consumption), high-density lipoprotein cholesterol (HDL-C)level, and the total cholesterol–HDL-C ratio. Results At 6 months, the HardI-HiF, HardI–low-frequency, and moderate-intensity–HiFconditions demonstrated significant increases in maximum oxygen consumption (P<.01for all), but only the HardI-HiF condition showed significant improvements in HDL-Clevel (P<.03), total cholesterol–HDL-C ratio (P<.04), and maximum oxygen consumption(P<.01) compared with physician advice. At 24 months, the increases in maximumoxygen consumption remained significantly higher than baseline in the HardI-HiF,HardI–low-frequency, and moderate-intensity–HiF conditions and in the HardI-HiFgroup compared with physician advice (P<.01 for all), but no significant effects onHDL-C level (P = .57) or total cholesterol–HDL-C ratio (P = .64) were observed. Conclusions Exercise counseling with a prescription for walking at either a HardIor a HiF produced significant long-term improvements in cardiorespiratory fitness.More exercise or the combination of HardI plus HiF exercise may provide additionalbenefits, including larger fitness changes and improved lipid profiles. ... Table 2. Observed Values for Cardiorespiratory Fitness and for Lipoproteins andLipids at Baseline and Change From Baseline to 6 Months by Condition========================== ----Condition*Variable----HardI-HiF (n = 86) ModI-HiF (n = 94) HardI-LowF (n = 80) ModI-LowF (n =73) PA (n = 78)==========================V^O2Max, L/min Baseline 2.09±0.69 2.04±0.59 2.03±0.58 2.20±0.60 2.00±0.55 Change 0.15±0.24†‡¶ 0.08±0.15† 0.07±0.18† 0.02±0.15 0.04±0.22TC, mg/dL Baseline 193.4±37.7 192.5±29.2 189.8±28.6 195.4±27.6 186.5±31.4 Change -1.3±18.0 0.9±15.9 -0.5±16.3 0.4±17.8 -0.3±15.0LDL-C, mg/dL Baseline 115.5±28.4 114.3±26.4 114.5±25.9 118.8±25.5 109.3±26.7 Change -2.2±14.4 1.0±14.3 -0.8±13.8 -1.0±14.5 0±13.7HDL-C, mg/dL Baseline 52.13±12.21 54.49±14.93 53.47±11.49 54.49±14.93 55.43±13.44 Change 1.83±6.11†‡¶ 0.54±6.43 -0.09±5.55 1.44±6.87 0.03±5.23TC/HDL-C ratio Baseline 3.89±1.09 3.78±1.09 3.71±0.95 4.02±1.33 3.55±1.02 Change -0.12±0.33†‡¶ 0.04±0.55 -0.02±0.46 -0.05±0.48 0.02±0.37TG, mg/dL Baseline 124.8±74.0 119.0±59.4 108.3±52.5 123.9±70.8 108.9±67.1 Change -6.9±40.7 8.4±46.6 2.4±29.4 -0.2±37.1 -2.1±33.3==========================Abbreviations: BMI, body mass index (calculated as weight in kilograms divided bythe square of height in meters); DBP, diastolic blood pressure; FBG, fastingbloodglucose; HardI, hard intensity; HDL-C, high-density lipoprotein cholesterol; HiF,high frequency; LDL-C, low-density lipoprotein cholesterol; LowF, low frequency;ModI, moderate intensity; PA, physician advice; SBP, systolic blood pressure; TC,total cholesterol; TG, triglycerides; V ÿ O2max, maximum oxygen consumption.SI conversion factors: To convert FBG to millimoles per liter, multiply by 0.0555;to convert HDL-C, LDL-C, and TC to millimoles per liter, multiply by 0.0259; and toconvert TG to millimoles per liter, multiply by 0.0113.*Data are given as mean±SD. The HardI-HiF, HardI-LowF, and ModI-HiF conditionsdemonstrated significant increases in V^O2Max (P<.01), but only theHardI-HiF condition showed significant improvements in HDL-C level, TC/HDL-C ratio,and V^O2Max, compared with the PA and ModI-LowF groups (P<.01 foreach). For more details, see the “Cardiorespiratory Fitness” and “Lipids,Lipoproteins, and Other Measures” subsections of the “Results” section.†Significant (P<.01) change from baseline.‡Significant (P<.01) change compared with the ModI-LowF condition.¶Significant (P<.01) change compared with the PA condition.Al Pater, PhD; email: old542000@...

[Guest guest]

Hi folks:

As far as I know, no one disputes that there is a phenomenon

called 'training effect' whereby if you exercise you become more able

to exercise. Or become 'more fit' in common parlance. But Dr. Henry

's opinion (cardiologist, Cornell Medical Centre, NYC) is

that: " .... fitness has absolutely nothing to do with

health ....... " - quote from his book 'The Exercise Myth'.

I believe it is also generally agreed that if unhealthy people

exercise moderately they may delay the onset of CVD, probably because

a bout of exercise, as I understand it, 'burns off' cholesterol until

the next dose of poor food restores it. So that if you exercise,

high levels of cholesterol in your blood are in contact with your

arteries only intermittently instead of continuously so deposits

accumulate more slowly.

Also it is agreed that a certain threshold level of exercise is vital

to health. So if you want to hear both sides of the argument read

's book along with Blair's studies and make up your own mind.

For those here who are well established in a CRON lifestyle - a BMI

of say 20, with very healthy food intake - the CVD benefits of

exercise seem to be irrelevant.

The issue I believe **we here** need to get a handle on is what is

that key threshold level for people on CRON, and how do we achieve it

with the least expenditure of calories?

It seems to me that a huge amount of scientific effort is being

expended these days trying to find ways to improve health that

studiously avoid the necessity of doing the obvious. Those research

resources would be better spent, imo, by studying how to further

improve health after having already implemented the obvious (CRON).

Rodney.

>

> > How's four more years sound to you, Rodney?

> >

> > http://tinyurl.com/cm3d7

>

> The whole story, All, is:

>

> In This Issue of Archives of Internal Medicine

> Arch Intern Med. 2005;165:2319.

> Prescribing Exercise at Varied Levels of Intensity and Frequency

>

> This randomized trial examined the effects of counseling free-

living, sedentary

> adults to exercise at different levels of intensity and frequency.

Significant

> improvements in cardiorespiratory fitness were achieved and

maintained over 24

> months via exercise counseling with a prescription for walking 30

minutes per day,

> either at a moderate intensity 5 to 7 days per week or at a hard

intensity 3 to 4

> days per week. Additional benefits, including larger changes in

fitness level and

> short-term increases in high-density lipoprotein cholesterol level,

were achieved by

> prescribing the combination of hard-intensity plus high-frequency

exercise.

>

> Editorials

> How Much and What Type of Physical Activity Is Enough?: What

Physicians Should Tell

> Their Patients

> N. Blair; J. LaMonte

> Arch Intern Med. 2005;165:2324-2325.

>

> Regular physical activity is associated with higher levels of

physical fitness,

> particularly aerobic power or cardiorespiratory fitness, favorable

chronic-disease

> risk-factor profiles, reduced risk of clinical events, and greater

longevity.1-4

> However, an incomplete understanding still exists as to the

specific dose of

> physical activity, in terms of frequency, intensity, and duration,

and the related

> volume of energy expenditure that is effective in achieving

specific biological or

> clinical outcomes.

>

> The report by Duncan et al5 in this issue of the ARCHIVES provides

important new

> information on patterns of exercise intensity and frequency in

relation to changes

> in cardiorespiratory fitness and cardiovascular disease (CVD) risk

factors. In this

> well-designed and well-conducted study, the investigators assigned

participants to

> physician-assisted counseling (the comparison group) or to 1 of 4

intervention

> groups composed of 2 exercise intensities (45%-55% or 65%-75% of

maximal heart rate

>

---

reserve) and 2 exercise frequencies (3-4 sessions/wk or 5-7

sessions/wk).

> Exercise intensity was objectively monitored using an electronic HR

recording

> device. Walking was the exercise modality, the duration of which

was constant (30

> min/d) for all intervention groups. Primary outcomes were changes in

> cardiorespiratory fitness (quantified as maximal oxygen uptake in

milliliters per

> kilogram per minute) and changes in selected CVD risk factors at 6

and 24 months

> after baseline. The intervention groups received intensive

behavioral counseling

> based on methods of demonstrated effectiveness in previous exercise

intervention

> trials. The investigators achieved acceptable adherence to the

interventions and to

> follow-up examinations.

>

> We comment here primarily on the changes observed in

cardiorespiratory fitness,

> which is a strong predictor of numerous health outcomes, including

morbidity and

> mortality,6-7 and is perhaps the best indicator of response to

aerobic exercise

> training. As illustrated in the Figure in the article by Duncan et

al,5

> high-intensity exercise (at either low or high frequency) and

moderate-intensity

> activity at high frequency show significant and similar increases

in fitness over

> baseline at 24 months. Participants in the moderate-intensity

activity at low

> frequency and physician-assisted counseling groups had

nonsignificant fitness

> increases of about 1% over baseline.

>

> Public health recommendations for physical activity1-4 vary

slightly in the several

> published reports, but the consensus is that the frequency should

be 5 d/wk or more

> of moderate-intensity physical activity for 30 min/d or a frequency

of 3 d/wk or

> more at vigorous intensity for 20 min/d. Definitions are different

in the various

> reports, but moderate intensity is typically defined as an absolute

intensity of 3

> to 6 metabolic equivalents (METs), and vigorous intensity as more

than 6 METs.

> Recommendations for moderate-intensity activity lead to total

exercise doses ranging

> from 7.5 to 15.0 MET h/wk.

>

> Duncan et al5 prescribed intensity on the basis of HR reserve,

which is a relative

> intensity and is influenced by age, health status, fitness level,

and activity

> pattern. The percentage of HR reserve is roughly comparable to the

percentage of

> maximal METs; and the maximal METs, as calculated from the maximal

oxygen uptake

> values reported in Table 1 in their article, were approximately 6.6

METs in women

> and 8.5 METs in men. These data yield total exercise dose targets

ranging from

> around 4.5 MET h/wk (about 338 kcal/wk for a 75-kg person) to as

much as 22.3 MET

> h/wk (about 1673 kcal/wk for a 75-kg person), with the lowest value

being the

> approximate dose for women in the moderate-intensity, low-frequency

group and the

> highest value being for men in the high-intensity, high-frequency

group. The total

> volume of exercise actually completed by study participants was 58%

to 66% of the

> prescribed dose, or ranging from 3.6 MET h/wk for the moderate-

intensity,

> low-frequency group to 6.8 MET h/wk for the high-intensity, high

frequency group.

> All doses of at least 4 MET h/wk, or about 300 kcal/wk for a 75-kg

person

> (moderate-intensity, high-frequency group), showed significant

increases in fitness

> over baseline. Thus, a dose of 4 MET h/wk appears to be beneficial,

even though this

> amount of weekly energy expenditure is a bit lower than the

consensus

> recommendation. Furthermore, individuals in the moderate-intensity,

high-frequency

> group achieved similar improvements in cardiorespiratory fitness to

those in either

> of the high-intensity groups.

>

> Although these observations must be generalized with caution, they

carry important

> public health and clinical implications. Because the exercise

modality was walking,

> which is the most prevalent form of physical activity reported by

US adults,1 the

> findings should be encouraging for health care providers who

counsel individuals on

> increasing their physical activity habits. Practitioners should

begin by presenting

> the consensus public health recommendation to their patients, with

the goal of

> increasing activity levels to 30 minutes of moderate-intensity

walking 5 d/wk or

> more. Practitioners can routinely encourage their patients to

strive for this dose,

> but they can expect that in some individuals, fitness and health

benefits may occur

> even if they do not attain it on a regular basis. The results

reported by Duncan et

> al5 indicate that health benefits may be achieved by some

individuals at the

> relatively low dose of 4 MET h/wk (about 300 kcal for a 75-kg

person). These

> findings should be generalized with caution until additional

randomized controlled

> trials are undertaken to confirm the observations.

>

> Other results of the study are worth noting. There was no

significant difference for

> adherence between the low- and high-frequency groups, suggesting

that recommending 5

> to 7 d/wk of exercise is not a deterrent. The finding that

participants in

> moderate-intensity groups had a significantly better adherence

(66%) than did

> participants in the high-intensity groups (58%) reinforces the

notion that

> moderate-intensity physical activity may be more acceptable than

strenuous physical

> activities, particularly for initially sedentary or physically

inactive adults such

> as those enrolled in this study.

>

> Duncan et al5 found that only the high-intensity, high-frequency

group showed

> significant improvements in high-density lipoprotein cholesterol

levels and in the

> total cholesterol/high-density lipoprotein cholesterol ratio. It

may well be that

> higher doses of physical activity are required to affect the lipid

profile. However,

> with the exception of being physically inactive and overweight, the

average baseline

> risk factor profile among the middle-aged study participants was

clinically normal.

> As indicated by the authors, persons with abnormal lipid levels

were excluded from

> the study, so it is possible that the exercise doses achieved by

these participants

> might have had some effect on those with abnormal lipid levels.

>

> Nonetheless, it is important to note that the health benefits of

physical activity

> and cardiorespiratory fitness extend beyond any effect they might

have on

> conventional chronic disease risk factors. Our research group has

shown substantial

> benefits of moderate levels of cardiorespiratory fitness in

relation to CVD or

> all-cause mortality, independent of age, sex, and conventional CVD

risk factors.6

> Moderate fitness also was associated with lower mortality risk in

numerous subgroups

> of our population, including those who were obese and men with

hypertension,

> diabetes, or metabolic syndrome.7-10 In fact, our data suggest that

being physically

> active and fit may be of particular importance for those who have

already expressed

> clinically relevant risk factor levels or chronic disease.7-8 Thus

it is important

> for practitioners and their patients to not judge the health

benefits of regular

> physical activity solely by its effect on conventional risk

factors; they should

> counsel their patients that regular activity is beneficial whether

or not it

> improves their lipid profile, blood pressure, weight, or glucose

tolerance.

>

> In summary, Duncan et al5 have demonstrated that various

combinations of exercise

> frequency and intensity, yielding a modest total physical activity

dose, can be

> effective in increasing aerobic power. Individuals who choose to

exercise at a

> higher intensity (65%-75% of maximal HR reserve) can make

significant improvements

> in their fitness by walking for 30 minutes 3 or 4 d/wk. Likewise,

persons who prefer

> a lower intensity of 45% to 55% can obtain similar benefits by

walking for 30

> minutes 5 to 7 d/wk. The findings reported by Duncan et al are

further evidence of

> the opportunity that practitioners have in counseling their

patients on a health

> behavior that has critical importance for primary and secondary

disease prevention.

>

> Our current work on topics relevant to this editorial is supported

in part by

> equipment grants from Life Fitness, Schiller Park, Ill

>

> Effects of Physical Activity on Life Expectancy With Cardiovascular

Disease

> H. Franco; de Laet; Peeters; Jonker;

Johan Mackenbach;

> Wilma Nusselder

> Arch Intern Med. 2005;165:2355-2360.

>

> ABSTRACT

>

> Background Physical inactivity is a modifiable risk factor for

cardiovascular

> disease. However, little is known about the effects of physical

activity on life

> expectancy with and without cardiovascular disease. Our objective

was to calculate

> the consequences of different physical activity levels after age 50

years on total

> life expectancy and life expectancy with and without cardiovascular

disease.

>

> Methods We constructed multistate life tables using data from the

Framingham Heart

> Study to calculate the effects of 3 levels of physical activity

(low, moderate, and

> high) among populations older than 50 years. For the life table

calculations, we

> used hazard ratios for 3 transitions (healthy to death, healthy to

disease, and

> disease to death) by levels of physical activity and adjusted for

age, sex, smoking,

> any comorbidity (cancer, left ventricular hypertrophy, arthritis,

diabetes, ankle

> edema, or pulmonary disease), and examination at start of follow-up

period.

>

> Results Moderate and high physical activity levels led to 1.3 and

3.7 years more in

> total life expectancy and 1.1 and 3.2 more years lived without

cardiovascular

> disease, respectively, for men aged 50 years or older compared with

those who

> maintained a low physical activity level. For women the differences

were 1.5 and 3.5

> years in total life expectancy and 1.3 and 3.3 more years lived

free of

> cardiovascular disease, respectively.

>

> Conclusions Avoiding a sedentary lifestyle during adulthood not

only prevents

> cardiovascular disease independently of other risk factors but also

substantially

> expands the total life expectancy and the cardiovascular disease–

free life

> expectancy for men and women. This effect is already seen at

moderate levels of

> physical activity, and the gains in cardiovascular disease–free

life expectancy are

> twice as large at higher activity levels.

>

> Prescribing Exercise at Varied Levels of Intensity and Frequency: A

Randomized Trial

> Glen E. Duncan; D. Anton; Sumner J. Sydeman; L.

Newton Jr; Joyce A.

> Corsica; E. Durning; U. Ketterson; A.

; n C.

> Limacher; G. Perri

> Arch Intern Med. 2005;165:2362-2369.

>

> ABSTRACT

>

> Background Regular physical activity produces beneficial effects

on health, but the

> exercise prescription needed to improve cardiovascular disease risk

factors in

> free-living sedentary individuals remains unclear.

>

> Methods Sedentary adults (N = 492, 64.0% women) were randomized to

1 of 4

> exercise-counseling conditions or to a physician advice comparison

group. The

> duration (30 minutes) and type (walking) of exercise were held

constant, while

> exercise intensity and frequency were manipulated to form 4

exercise prescriptions:

> moderate intensity–low frequency, moderate intensity–high frequency

(HiF), hard

> intensity (HardI)–low frequency, and HardI-HiF. Comparison group

participants

> received physician advice and written materials regarding

recommended levels of

> exercise for health. Outcomes included 6- and 24-month changes in

cardiorespiratory

> fitness (maximum oxygen consumption), high-density lipoprotein

cholesterol (HDL-C)

> level, and the total cholesterol–HDL-C ratio.

>

> Results At 6 months, the HardI-HiF, HardI–low-frequency, and

moderate-intensity–HiF

> conditions demonstrated significant increases in maximum oxygen

consumption (P<.01

> for all), but only the HardI-HiF condition showed significant

improvements in HDL-C

> level (P<.03), total cholesterol–HDL-C ratio (P<.04), and maximum

oxygen consumption

> (P<.01) compared with physician advice. At 24 months, the increases

in maximum

> oxygen consumption remained significantly higher than baseline in

the HardI-HiF,

> HardI–low-frequency, and moderate-intensity–HiF conditions and in

the HardI-HiF

> group compared with physician advice (P<.01 for all), but no

significant effects on

> HDL-C level (P = .57) or total cholesterol–HDL-C ratio (P = .64)

were observed.

>

> Conclusions Exercise counseling with a prescription for walking at

either a HardI

> or a HiF produced significant long-term improvements in

cardiorespiratory fitness.

> More exercise or the combination of HardI plus HiF exercise may

provide additional

> benefits, including larger fitness changes and improved lipid

profiles.

>

> ... Table 2. Observed Values for Cardiorespiratory Fitness and for

Lipoproteins and

> Lipids at Baseline and Change From Baseline to 6 Months by Condition

> ==========================

> ----Condition*

> Variable----HardI-HiF (n = 86) ModI-HiF (n = 94) HardI-LowF (n =

80) ModI-LowF (n =

> 73) PA (n = 78)

> ==========================

> V^O2Max, L/min

> Baseline 2.09±0.69 2.04±0.59 2.03±0.58 2.20±0.60 2.00±0.55

> Change 0.15±0.24†‡¶ 0.08±0.15† 0.07±0.18† 0.02±0.15 0.04±0.22

> TC, mg/dL

> Baseline 193.4±37.7 192.5±29.2 189.8±28.6 195.4±27.6 186.5±31.4

> Change -1.3±18.0 0.9±15.9 -0.5±16.3 0.4±17.8 -0.3±15.0

> LDL-C, mg/dL

> Baseline 115.5±28.4 114.3±26.4 114.5±25.9 118.8±25.5 109.3±26.7

> Change -2.2±14.4 1.0±14.3 -0.8±13.8 -1.0±14.5 0±13.7

> HDL-C, mg/dL

> Baseline 52.13±12.21 54.49±14.93 53.47±11.49 54.49±14.93

55.43±13.44

> Change 1.83±6.11†‡¶ 0.54±6.43 -0.09±5.55 1.44±6.87 0.03±5.23

> TC/HDL-C ratio

> Baseline 3.89±1.09 3.78±1.09 3.71±0.95 4.02±1.33 3.55±1.02

> Change -0.12±0.33†‡¶ 0.04±0.55 -0.02±0.46 -0.05±0.48 0.02±0.37

> TG, mg/dL

> Baseline 124.8±74.0 119.0±59.4 108.3±52.5 123.9±70.8 108.9±67.1

> Change -6.9±40.7 8.4±46.6 2.4±29.4 -0.2±37.1 -2.1±33.3

> ==========================

> Abbreviations: BMI, body mass index (calculated as weight in

kilograms divided by

> the square of height in meters); DBP, diastolic blood pressure;

FBG, fastingblood

> glucose; HardI, hard intensity; HDL-C, high-density lipoprotein

cholesterol; HiF,

> high frequency; LDL-C, low-density lipoprotein cholesterol; LowF,

low frequency;

> ModI, moderate intensity; PA, physician advice; SBP, systolic blood

pressure; TC,

> total cholesterol; TG, triglycerides; V ÿ O2max, maximum oxygen

consumption.

> SI conversion factors: To convert FBG to millimoles per liter,

multiply by 0.0555;

> to convert HDL-C, LDL-C, and TC to millimoles per liter, multiply

by 0.0259; and to

> convert TG to millimoles per liter, multiply by 0.0113.

> *Data are given as mean±SD. The HardI-HiF, HardI-LowF, and ModI-HiF

conditions

> demonstrated significant increases in V^O2Max (P<.01), but only the

> HardI-HiF condition showed significant improvements in HDL-C level,

TC/HDL-C ratio,

> and V^O2Max, compared with the PA and ModI-LowF groups (P<.01 for

> each). For more details, see the " Cardiorespiratory Fitness "

and " Lipids,

> Lipoproteins, and Other Measures " subsections of the " Results "

section.

> †Significant (P<.01) change from baseline.

> ‡Significant (P<.01) change compared with the ModI-LowF condition.

> ¶Significant (P<.01) change compared with the PA condition.

>

> Al Pater, PhD; email: old542000@y...

>

>

>

>

> __________________________________

> - PC Magazine Editors' Choice 2005

> http://mail.

>

[Guest guest]

Hi folks:

As far as I know, no one disputes that there is a phenomenon

called 'training effect' whereby if you exercise you become more able

to exercise. Or become 'more fit' in common parlance. But Dr. Henry

's opinion (cardiologist, Cornell Medical Centre, NYC) is

that: " .... fitness has absolutely nothing to do with

health ....... " - quote from his book 'The Exercise Myth'.

I believe it is also generally agreed that if unhealthy people

exercise moderately they may delay the onset of CVD, probably because

a bout of exercise, as I understand it, 'burns off' cholesterol until

the next dose of poor food restores it. So that if you exercise,

high levels of cholesterol in your blood are in contact with your

arteries only intermittently instead of continuously so deposits

accumulate more slowly.

Also it is agreed that a certain threshold level of exercise is vital

to health. So if you want to hear both sides of the argument read

's book along with Blair's studies and make up your own mind.

For those here who are well established in a CRON lifestyle - a BMI

of say 20, with very healthy food intake - the CVD benefits of

exercise seem to be irrelevant.

The issue I believe **we here** need to get a handle on is what is

that key threshold level for people on CRON, and how do we achieve it

with the least expenditure of calories?

It seems to me that a huge amount of scientific effort is being

expended these days trying to find ways to improve health that

studiously avoid the necessity of doing the obvious. Those research

resources would be better spent, imo, by studying how to further

improve health after having already implemented the obvious (CRON).

Rodney.

>

> > How's four more years sound to you, Rodney?

> >

> > http://tinyurl.com/cm3d7

>

> The whole story, All, is:

>

> In This Issue of Archives of Internal Medicine

> Arch Intern Med. 2005;165:2319.

> Prescribing Exercise at Varied Levels of Intensity and Frequency

>

> This randomized trial examined the effects of counseling free-

living, sedentary

> adults to exercise at different levels of intensity and frequency.

Significant

> improvements in cardiorespiratory fitness were achieved and

maintained over 24

> months via exercise counseling with a prescription for walking 30

minutes per day,

> either at a moderate intensity 5 to 7 days per week or at a hard

intensity 3 to 4

> days per week. Additional benefits, including larger changes in

fitness level and

> short-term increases in high-density lipoprotein cholesterol level,

were achieved by

> prescribing the combination of hard-intensity plus high-frequency

exercise.

>

> Editorials

> How Much and What Type of Physical Activity Is Enough?: What

Physicians Should Tell

> Their Patients

> N. Blair; J. LaMonte

> Arch Intern Med. 2005;165:2324-2325.

>

> Regular physical activity is associated with higher levels of

physical fitness,

> particularly aerobic power or cardiorespiratory fitness, favorable

chronic-disease

> risk-factor profiles, reduced risk of clinical events, and greater

longevity.1-4

> However, an incomplete understanding still exists as to the

specific dose of

> physical activity, in terms of frequency, intensity, and duration,

and the related

> volume of energy expenditure that is effective in achieving

specific biological or

> clinical outcomes.

>

> The report by Duncan et al5 in this issue of the ARCHIVES provides

important new

> information on patterns of exercise intensity and frequency in

relation to changes

> in cardiorespiratory fitness and cardiovascular disease (CVD) risk

factors. In this

> well-designed and well-conducted study, the investigators assigned

participants to

> physician-assisted counseling (the comparison group) or to 1 of 4

intervention

> groups composed of 2 exercise intensities (45%-55% or 65%-75% of

maximal heart rate

>

---

reserve) and 2 exercise frequencies (3-4 sessions/wk or 5-7

sessions/wk).

> Exercise intensity was objectively monitored using an electronic HR

recording

> device. Walking was the exercise modality, the duration of which

was constant (30

> min/d) for all intervention groups. Primary outcomes were changes in

> cardiorespiratory fitness (quantified as maximal oxygen uptake in

milliliters per

> kilogram per minute) and changes in selected CVD risk factors at 6

and 24 months

> after baseline. The intervention groups received intensive

behavioral counseling

> based on methods of demonstrated effectiveness in previous exercise

intervention

> trials. The investigators achieved acceptable adherence to the

interventions and to

> follow-up examinations.

>

> We comment here primarily on the changes observed in

cardiorespiratory fitness,

> which is a strong predictor of numerous health outcomes, including

morbidity and

> mortality,6-7 and is perhaps the best indicator of response to

aerobic exercise

> training. As illustrated in the Figure in the article by Duncan et

al,5

> high-intensity exercise (at either low or high frequency) and

moderate-intensity

> activity at high frequency show significant and similar increases

in fitness over

> baseline at 24 months. Participants in the moderate-intensity

activity at low

> frequency and physician-assisted counseling groups had

nonsignificant fitness

> increases of about 1% over baseline.

>

> Public health recommendations for physical activity1-4 vary

slightly in the several

> published reports, but the consensus is that the frequency should

be 5 d/wk or more

> of moderate-intensity physical activity for 30 min/d or a frequency

of 3 d/wk or

> more at vigorous intensity for 20 min/d. Definitions are different

in the various

> reports, but moderate intensity is typically defined as an absolute

intensity of 3

> to 6 metabolic equivalents (METs), and vigorous intensity as more

than 6 METs.

> Recommendations for moderate-intensity activity lead to total

exercise doses ranging

> from 7.5 to 15.0 MET h/wk.

>

> Duncan et al5 prescribed intensity on the basis of HR reserve,

which is a relative

> intensity and is influenced by age, health status, fitness level,

and activity

> pattern. The percentage of HR reserve is roughly comparable to the

percentage of

> maximal METs; and the maximal METs, as calculated from the maximal

oxygen uptake

> values reported in Table 1 in their article, were approximately 6.6

METs in women

> and 8.5 METs in men. These data yield total exercise dose targets

ranging from

> around 4.5 MET h/wk (about 338 kcal/wk for a 75-kg person) to as

much as 22.3 MET

> h/wk (about 1673 kcal/wk for a 75-kg person), with the lowest value

being the

> approximate dose for women in the moderate-intensity, low-frequency

group and the

> highest value being for men in the high-intensity, high-frequency

group. The total

> volume of exercise actually completed by study participants was 58%

to 66% of the

> prescribed dose, or ranging from 3.6 MET h/wk for the moderate-

intensity,

> low-frequency group to 6.8 MET h/wk for the high-intensity, high

frequency group.

> All doses of at least 4 MET h/wk, or about 300 kcal/wk for a 75-kg

person

> (moderate-intensity, high-frequency group), showed significant

increases in fitness

> over baseline. Thus, a dose of 4 MET h/wk appears to be beneficial,

even though this

> amount of weekly energy expenditure is a bit lower than the

consensus

> recommendation. Furthermore, individuals in the moderate-intensity,

high-frequency

> group achieved similar improvements in cardiorespiratory fitness to

those in either

> of the high-intensity groups.

>

> Although these observations must be generalized with caution, they

carry important

> public health and clinical implications. Because the exercise

modality was walking,

> which is the most prevalent form of physical activity reported by

US adults,1 the

> findings should be encouraging for health care providers who

counsel individuals on

> increasing their physical activity habits. Practitioners should

begin by presenting

> the consensus public health recommendation to their patients, with

the goal of

> increasing activity levels to 30 minutes of moderate-intensity

walking 5 d/wk or

> more. Practitioners can routinely encourage their patients to

strive for this dose,

> but they can expect that in some individuals, fitness and health

benefits may occur

> even if they do not attain it on a regular basis. The results

reported by Duncan et

> al5 indicate that health benefits may be achieved by some

individuals at the

> relatively low dose of 4 MET h/wk (about 300 kcal for a 75-kg

person). These

> findings should be generalized with caution until additional

randomized controlled

> trials are undertaken to confirm the observations.

>

> Other results of the study are worth noting. There was no

significant difference for

> adherence between the low- and high-frequency groups, suggesting

that recommending 5

> to 7 d/wk of exercise is not a deterrent. The finding that

participants in

> moderate-intensity groups had a significantly better adherence

(66%) than did

> participants in the high-intensity groups (58%) reinforces the

notion that

> moderate-intensity physical activity may be more acceptable than

strenuous physical

> activities, particularly for initially sedentary or physically

inactive adults such

> as those enrolled in this study.

>

> Duncan et al5 found that only the high-intensity, high-frequency

group showed

> significant improvements in high-density lipoprotein cholesterol

levels and in the

> total cholesterol/high-density lipoprotein cholesterol ratio. It

may well be that

> higher doses of physical activity are required to affect the lipid

profile. However,

> with the exception of being physically inactive and overweight, the

average baseline

> risk factor profile among the middle-aged study participants was

clinically normal.

> As indicated by the authors, persons with abnormal lipid levels

were excluded from

> the study, so it is possible that the exercise doses achieved by

these participants

> might have had some effect on those with abnormal lipid levels.

>

> Nonetheless, it is important to note that the health benefits of

physical activity

> and cardiorespiratory fitness extend beyond any effect they might

have on

> conventional chronic disease risk factors. Our research group has

shown substantial

> benefits of moderate levels of cardiorespiratory fitness in

relation to CVD or

> all-cause mortality, independent of age, sex, and conventional CVD

risk factors.6

> Moderate fitness also was associated with lower mortality risk in

numerous subgroups

> of our population, including those who were obese and men with

hypertension,

> diabetes, or metabolic syndrome.7-10 In fact, our data suggest that

being physically

> active and fit may be of particular importance for those who have

already expressed

> clinically relevant risk factor levels or chronic disease.7-8 Thus

it is important

> for practitioners and their patients to not judge the health

benefits of regular

> physical activity solely by its effect on conventional risk

factors; they should

> counsel their patients that regular activity is beneficial whether

or not it

> improves their lipid profile, blood pressure, weight, or glucose

tolerance.

>

> In summary, Duncan et al5 have demonstrated that various

combinations of exercise

> frequency and intensity, yielding a modest total physical activity

dose, can be

> effective in increasing aerobic power. Individuals who choose to

exercise at a

> higher intensity (65%-75% of maximal HR reserve) can make

significant improvements

> in their fitness by walking for 30 minutes 3 or 4 d/wk. Likewise,

persons who prefer

> a lower intensity of 45% to 55% can obtain similar benefits by

walking for 30

> minutes 5 to 7 d/wk. The findings reported by Duncan et al are

further evidence of

> the opportunity that practitioners have in counseling their

patients on a health

> behavior that has critical importance for primary and secondary

disease prevention.

>

> Our current work on topics relevant to this editorial is supported

in part by

> equipment grants from Life Fitness, Schiller Park, Ill

>

> Effects of Physical Activity on Life Expectancy With Cardiovascular

Disease

> H. Franco; de Laet; Peeters; Jonker;

Johan Mackenbach;

> Wilma Nusselder

> Arch Intern Med. 2005;165:2355-2360.

>

> ABSTRACT

>

> Background Physical inactivity is a modifiable risk factor for

cardiovascular

> disease. However, little is known about the effects of physical

activity on life

> expectancy with and without cardiovascular disease. Our objective

was to calculate

> the consequences of different physical activity levels after age 50

years on total

> life expectancy and life expectancy with and without cardiovascular

disease.

>

> Methods We constructed multistate life tables using data from the

Framingham Heart

> Study to calculate the effects of 3 levels of physical activity

(low, moderate, and

> high) among populations older than 50 years. For the life table

calculations, we

> used hazard ratios for 3 transitions (healthy to death, healthy to

disease, and

> disease to death) by levels of physical activity and adjusted for

age, sex, smoking,

> any comorbidity (cancer, left ventricular hypertrophy, arthritis,

diabetes, ankle

> edema, or pulmonary disease), and examination at start of follow-up

period.

>

> Results Moderate and high physical activity levels led to 1.3 and

3.7 years more in

> total life expectancy and 1.1 and 3.2 more years lived without

cardiovascular

> disease, respectively, for men aged 50 years or older compared with

those who

> maintained a low physical activity level. For women the differences

were 1.5 and 3.5

> years in total life expectancy and 1.3 and 3.3 more years lived

free of

> cardiovascular disease, respectively.

>

> Conclusions Avoiding a sedentary lifestyle during adulthood not

only prevents

> cardiovascular disease independently of other risk factors but also

substantially

> expands the total life expectancy and the cardiovascular disease–

free life

> expectancy for men and women. This effect is already seen at

moderate levels of

> physical activity, and the gains in cardiovascular disease–free

life expectancy are

> twice as large at higher activity levels.

>

> Prescribing Exercise at Varied Levels of Intensity and Frequency: A

Randomized Trial

> Glen E. Duncan; D. Anton; Sumner J. Sydeman; L.

Newton Jr; Joyce A.

> Corsica; E. Durning; U. Ketterson; A.

; n C.

> Limacher; G. Perri

> Arch Intern Med. 2005;165:2362-2369.

>

> ABSTRACT

>

> Background Regular physical activity produces beneficial effects

on health, but the

> exercise prescription needed to improve cardiovascular disease risk

factors in

> free-living sedentary individuals remains unclear.

>

> Methods Sedentary adults (N = 492, 64.0% women) were randomized to

1 of 4

> exercise-counseling conditions or to a physician advice comparison

group. The

> duration (30 minutes) and type (walking) of exercise were held

constant, while

> exercise intensity and frequency were manipulated to form 4

exercise prescriptions:

> moderate intensity–low frequency, moderate intensity–high frequency

(HiF), hard

> intensity (HardI)–low frequency, and HardI-HiF. Comparison group

participants

> received physician advice and written materials regarding

recommended levels of

> exercise for health. Outcomes included 6- and 24-month changes in

cardiorespiratory

> fitness (maximum oxygen consumption), high-density lipoprotein

cholesterol (HDL-C)

> level, and the total cholesterol–HDL-C ratio.

>

> Results At 6 months, the HardI-HiF, HardI–low-frequency, and

moderate-intensity–HiF

> conditions demonstrated significant increases in maximum oxygen

consumption (P<.01

> for all), but only the HardI-HiF condition showed significant

improvements in HDL-C

> level (P<.03), total cholesterol–HDL-C ratio (P<.04), and maximum

oxygen consumption

> (P<.01) compared with physician advice. At 24 months, the increases

in maximum

> oxygen consumption remained significantly higher than baseline in

the HardI-HiF,

> HardI–low-frequency, and moderate-intensity–HiF conditions and in

the HardI-HiF

> group compared with physician advice (P<.01 for all), but no

significant effects on

> HDL-C level (P = .57) or total cholesterol–HDL-C ratio (P = .64)

were observed.

>

> Conclusions Exercise counseling with a prescription for walking at

either a HardI

> or a HiF produced significant long-term improvements in

cardiorespiratory fitness.

> More exercise or the combination of HardI plus HiF exercise may

provide additional

> benefits, including larger fitness changes and improved lipid

profiles.

>

> ... Table 2. Observed Values for Cardiorespiratory Fitness and for

Lipoproteins and

> Lipids at Baseline and Change From Baseline to 6 Months by Condition

> ==========================

> ----Condition*

> Variable----HardI-HiF (n = 86) ModI-HiF (n = 94) HardI-LowF (n =

80) ModI-LowF (n =

> 73) PA (n = 78)

> ==========================

> V^O2Max, L/min

> Baseline 2.09±0.69 2.04±0.59 2.03±0.58 2.20±0.60 2.00±0.55

> Change 0.15±0.24†‡¶ 0.08±0.15† 0.07±0.18† 0.02±0.15 0.04±0.22

> TC, mg/dL

> Baseline 193.4±37.7 192.5±29.2 189.8±28.6 195.4±27.6 186.5±31.4

> Change -1.3±18.0 0.9±15.9 -0.5±16.3 0.4±17.8 -0.3±15.0

> LDL-C, mg/dL

> Baseline 115.5±28.4 114.3±26.4 114.5±25.9 118.8±25.5 109.3±26.7

> Change -2.2±14.4 1.0±14.3 -0.8±13.8 -1.0±14.5 0±13.7

> HDL-C, mg/dL

> Baseline 52.13±12.21 54.49±14.93 53.47±11.49 54.49±14.93

55.43±13.44

> Change 1.83±6.11†‡¶ 0.54±6.43 -0.09±5.55 1.44±6.87 0.03±5.23

> TC/HDL-C ratio

> Baseline 3.89±1.09 3.78±1.09 3.71±0.95 4.02±1.33 3.55±1.02

> Change -0.12±0.33†‡¶ 0.04±0.55 -0.02±0.46 -0.05±0.48 0.02±0.37

> TG, mg/dL

> Baseline 124.8±74.0 119.0±59.4 108.3±52.5 123.9±70.8 108.9±67.1

> Change -6.9±40.7 8.4±46.6 2.4±29.4 -0.2±37.1 -2.1±33.3

> ==========================

> Abbreviations: BMI, body mass index (calculated as weight in

kilograms divided by

> the square of height in meters); DBP, diastolic blood pressure;

FBG, fastingblood

> glucose; HardI, hard intensity; HDL-C, high-density lipoprotein

cholesterol; HiF,

> high frequency; LDL-C, low-density lipoprotein cholesterol; LowF,

low frequency;

> ModI, moderate intensity; PA, physician advice; SBP, systolic blood

pressure; TC,

> total cholesterol; TG, triglycerides; V ÿ O2max, maximum oxygen

consumption.

> SI conversion factors: To convert FBG to millimoles per liter,

multiply by 0.0555;

> to convert HDL-C, LDL-C, and TC to millimoles per liter, multiply

by 0.0259; and to

> convert TG to millimoles per liter, multiply by 0.0113.

> *Data are given as mean±SD. The HardI-HiF, HardI-LowF, and ModI-HiF

conditions

> demonstrated significant increases in V^O2Max (P<.01), but only the

> HardI-HiF condition showed significant improvements in HDL-C level,

TC/HDL-C ratio,

> and V^O2Max, compared with the PA and ModI-LowF groups (P<.01 for

> each). For more details, see the " Cardiorespiratory Fitness "

and " Lipids,

> Lipoproteins, and Other Measures " subsections of the " Results "

section.

> †Significant (P<.01) change from baseline.

> ‡Significant (P<.01) change compared with the ModI-LowF condition.

> ¶Significant (P<.01) change compared with the PA condition.

>

> Al Pater, PhD; email: old542000@y...

>

>

>

>

> __________________________________

> - PC Magazine Editors' Choice 2005

> http://mail.

>