Re: Grip Strength, BMI and Mortality

[Guest guest]

Excuse me. Let's scroll down to the RESULTS.

At 05:03 PM 2/21/2007, you wrote:

Hi folks:

Here are some interesting data, from the abstract below:

Grip strength is periodically noted to be a biomarker for longevity.

The higher the better. Here are this study's mortality data broken

out by BMI and grip strength:

Mortality (Indexed to the rate for BMI 20-25 with stronger grip

strength as equal to 100)

------- ----- grip strength -----

------- weaker - medium - stronger

--BMI-- ------- -------- ---------

--<20-- --136-- --127--- ---92----

-20-25- --125-- --114--- --100----

--25+-- --139-- --127--- --114----

Observations:

These data indicate that: it is better to be stronger than weaker;

people with a BMI above 25 have highest mortality at each level of

grip strength! : ^ ))) ; people with BMI below 20 have high

mortality if they have weaker grip strength, but THE LOWEST MORTALITY

if they have good grip strength.

This looks very supportive of the idea that the higher mortality

often reported at low BMIs is a function of sub-clinical illness that

may often also be reflected in poor muscle strength.

Yes I know. Someone is gonna say that it suggests there may be a

benefit to exercise to increase muscle strength : ^ )))

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

J Gerontol A Biol Sci Med Sci. 2000 Mar;55(3):M168-73.

" Muscle strength and body mass index as long-term predictors of

mortality in initially healthy men. "

Rantanen T, T, Leveille SG, Visser M, Foley D, Masaki K,

Guralnik JM.

Epidemiology, Demography and Biometry Program, National Institute on

Aging, National Institutes of Health, Bethesda, land, USA.

Taina@...

" BACKGROUND: Muscle weakness, low body weight, and chronic diseases

are often observed in the same people; however, the association of

muscle strength with mortality, independent of disease status and

body weight, has not been elucidated. The aim was to assess hand grip

strength as a predictor of all-cause mortality within different

levels of body mass index (BMI) in initially disease-free men.

METHODS: Mortality was followed prospectively over 30 years. Maximal

hand grip strength tests and BMI assessments were done at baseline in

1965 to 1970. The participants were 6040 healthy men aged 45 to 68

years at baseline living on Oahu, Hawaii.

RESULTS: The death rates

per 1000 person years were 24.6 in those with BMI <20, 18.5 in the

middle BMI category, and 18.0 in those with BMI > or = 25.

Umm, that doesn't sound like particularly CR-friendly news, and it

implies that overall, grip strength is lousier with lower BMI, and much

lousier for less-than-20 BMI people.

For grip

strength tertiles, the mortality rates were 24.8 in the lowest, 18.5

in the middle, and 14.0 in the highest third. In regression

models, within each tertile of grip strength, BMI showed only minimal

effect on mortality.

But an inverse relationship, apparently, to the extent it did

correlate.

In contrast, in each category of

BMI there was a

gradient of decreasing mortality risk with increasing grip strength.

Among those with BMI <20, the adjusted relative risks (RRs) of

mortality over 30 years were 1.36 (95% confidence interval 1.14-1.63)

for those in the lowest third of strength at baseline, 1.27 (1.02-

1.58) in the middle, and 0.92 (0.66-1.29) in the highest third.

Not highest third of low-BMI people, but the lowest third of people

overall. Hence the inference, from the BMI-mortality data, that very,

very few low-BMI people achieve the highest third of strength.

Maco

Correspondingly, for those with

BMI 20-24.99, the RRs of death were

1.25 (1.08-1.45), 1.14 (1.00-1.32), and 1.0 (reference) in the

lowest, middle, and highest third of grip strength, respectively. In

those with BMI > or =25, the RRs were 1.39 (1.16-1.65) in the lowest,

1.27 (1.08-1.49) in the middle, and 1.14 (0.98-1.32) in the highest

third of grip strength. Models were adjusted for age, education,

occupation, smoking, physical activity, and body height. CONCLUSIONS:

In healthy middle-aged men, long-term mortality risk was associated

with grip strength at baseline, independent of BMI. The possible

interpretation of the finding is that early life influences on muscle

strength may have long-term implications for mortality. Additionally,

higher strength itself may provide greater physiologic and functional

reserve that protects against mortality. "

PMID: 10795731

[Guest guest]

Seems to me that a better biomarker is squatting strength, that is the

ability and strength one has to squat all way down and back up.

Gripping strength may be a proxy for this and general level of

strength in muscle, and is utilized because it is easier to measure.

To my mind lower extremity and lower back (lumbar) strength (and

flexibility) is far more significant because of the fundamental

importance of locomotion and manipulation of one's body through space.

Bad knees, bad back, weak back and legs spells trouble.

Watch people's gait, how they move through space. You can spot those

whose locomotion is suffering and on a slow decline. What does this

portend for their future mobility and ease of movement into advancing age?

The strength of one's thighs, glutes and lumbar muscles is more

significant than forearm strength, imo.

bill

>

> Hi folks:

>

> Here are some interesting data, from the abstract below:

>

> Grip strength is periodically noted to be a biomarker for longevity.

> The higher the better. Here are this study's mortality data broken

> out by BMI and grip strength:

>

> Mortality (Indexed to the rate for BMI 20-25 with stronger grip

> strength as equal to 100)

>

> ------- ----- grip strength -----

> ------- weaker - medium - stronger

> --BMI-- ------- -------- ---------

> --<20-- --136-- --127--- ---92----

> -20-25- --125-- --114--- --100----

> --25+-- --139-- --127--- --114----

>

> Observations:

>

> These data indicate that: it is better to be stronger than weaker;

> people with a BMI above 25 have highest mortality at each level of

> grip strength! : ^ ))) ; people with BMI below 20 have high

> mortality if they have weaker grip strength, but THE LOWEST MORTALITY

> if they have good grip strength.

>

> This looks very supportive of the idea that the higher mortality

> often reported at low BMIs is a function of sub-clinical illness that

> may often also be reflected in poor muscle strength.

>

> Yes I know. Someone is gonna say that it suggests there may be a

> benefit to exercise to increase muscle strength : ^ )))

>

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

> J Gerontol A Biol Sci Med Sci. 2000 Mar;55(3):M168-73.

>

> " Muscle strength and body mass index as long-term predictors of

> mortality in initially healthy men. "

>

> Rantanen T, T, Leveille SG, Visser M, Foley D, Masaki K,

> Guralnik JM.

>

> Epidemiology, Demography and Biometry Program, National Institute on

> Aging, National Institutes of Health, Bethesda, land, USA.

> Taina@...

>

> " BACKGROUND: Muscle weakness, low body weight, and chronic diseases

> are often observed in the same people; however, the association of

> muscle strength with mortality, independent of disease status and

> body weight, has not been elucidated. The aim was to assess hand grip

> strength as a predictor of all-cause mortality within different

> levels of body mass index (BMI) in initially disease-free men.

> METHODS: Mortality was followed prospectively over 30 years. Maximal

> hand grip strength tests and BMI assessments were done at baseline in

> 1965 to 1970. The participants were 6040 healthy men aged 45 to 68

> years at baseline living on Oahu, Hawaii. RESULTS: The death rates

> per 1000 person years were 24.6 in those with BMI <20, 18.5 in the

> middle BMI category, and 18.0 in those with BMI > or = 25. For grip

> strength tertiles, the mortality rates were 24.8 in the lowest, 18.5

> in the middle, and 14.0 in the highest third. In regression

> models, within each tertile of grip strength, BMI showed only minimal

> effect on mortality. In contrast, in each category of BMI there was a

> gradient of decreasing mortality risk with increasing grip strength.

> Among those with BMI <20, the adjusted relative risks (RRs) of

> mortality over 30 years were 1.36 (95% confidence interval 1.14-1.63)

> for those in the lowest third of strength at baseline, 1.27 (1.02-

> 1.58) in the middle, and 0.92 (0.66-1.29) in the highest third.

> Correspondingly, for those with BMI 20-24.99, the RRs of death were

> 1.25 (1.08-1.45), 1.14 (1.00-1.32), and 1.0 (reference) in the

> lowest, middle, and highest third of grip strength, respectively. In

> those with BMI > or =25, the RRs were 1.39 (1.16-1.65) in the lowest,

> 1.27 (1.08-1.49) in the middle, and 1.14 (0.98-1.32) in the highest

> third of grip strength. Models were adjusted for age, education,

> occupation, smoking, physical activity, and body height. CONCLUSIONS:

> In healthy middle-aged men, long-term mortality risk was associated

> with grip strength at baseline, independent of BMI. The possible

> interpretation of the finding is that early life influences on muscle

> strength may have long-term implications for mortality. Additionally,

> higher strength itself may provide greater physiologic and functional

> reserve that protects against mortality. "

>

> PMID: 10795731

>

> Rodney.

>

[Guest guest]

The study on grip strength and BMI seems to show that it is important

to be strong to survive. Last November, we discussed the paper by

Calle[1] showing that the lowest mortality was associated with a BMI

of 23.5 to 24.9 in men and 22.0 to 23.4 in women. Presumably the

higher BMIs are associated with greater muscular strength, rather than

increased body fat.

It seems that to live long, it is necessary to be slim enough to avoid

diabetes and CVD, but strong enough to be able to overcome the

adversities that we face every day, like preventing falls. Muscular

strength may also be indicative of other life-extending features,

e.g., an improved immune system or improved metabolism.

PMID: 15487904 suggests that athletic conditioning may increase

maximal oxygen uptake, oxidative enzyme activities, and may also have

other positive changes in single muscle fiber size and metabolic

properties.

Minimizing BMI and neglecting strength-building exercises may not be

the right strategy for human longevity.

Tony

===

------- ----- grip strength -----

------- weaker - medium - stronger

--BMI-- ------- -------- ---------

--<20-- --136-- --127--- ---92----

-20-25- --125-- --114--- --100----

--25+-- --139-- --127--- --114----

[1] Calle EE, Thun MJ, Petrelli JM, C, Heath CW

Jr.

Body-mass index and mortality in a prospective cohort

of U.S. adults.

N Engl J Med. 1999 Oct 7;341(15):1097-105.

PMID: 10511607 http://tinyurl.com/k2jzg

" In healthy people who had never smoked, the nadir of the curve for

body-mass index and mortality was found at a body-mass index of 23.5

to 24.9 in men and 22.0 to 23.4 in women. "

[Guest guest]

Hi Maco:

I think we agree. If people have a low BMI (<20) because they are

sick and in consequence have a poor appetite and weak grip strength,

then it is to be expected they will have higher mortality.

It is also to be expected that only a small minority have whatever it

is that is required to restrain food intake to a level that maintains

a low BMI ..... despite having " a 'very healthy' appetite " and

having to put up with eating a lot less than they would like to eat on

a daily basis. Fortunately, the latter group is us, IMO. How many

people on the planet are following a CRON diet these days, despite

widespread publicity about it the past few years? A few thousand?

Maybe.

So who are all these other, non-CRON, people who have a BMI below 20?

[There aren't many of them over the age of 30 either, incidentally, as

can readily be ascertained on a visit to the mall, or by noting that

the average person my gender and age has a BMI of twenty-nine-point-

something these days]. Among these are those who have a digestive

system issue resulting in failure to absorb nutrients in much of what

they eat, very likely on a selective basis. Others just 'don't feel

up to' eating. The only times I have ever felt like that have been

when I was ill.

So, imo, those who 'naturally' have a BMI below 20 without having to

make an effort to achieve it are, often subclinically, sick. And the

majority of them will be malnourished also, either because of the

difficulties of obtaining the RDAs of nutrients at low intakes, or

because of a selective failure to absorb key nutrients. Intuition

suggests they would have higher mortality, and they are represented by

those shown to have BMI<20 and lower grip strength in that paper.

Those who are healthy, and manage to maintain a sensible BMI despite

the temptations to do otherwise, are represented by those with BMI<20

and higher grip strength. And yes, we do not represent a high

percentage of the total population. The reason why in my post I

presented these data in tabular form was because, for me at least, it

makes the situation far clearer than when recited in the form of text.

The data in the referenced study seem to me to support this

interpretation. So too, of course, do the data from mice, rats,

monkeys, flies, yeasts, spiders, etc., where fundamentally healthy

individuals with normal appetites, when permitted restricted but

adequate food intake, have much lower body weights and live one heck

of a lot longer.

The other, rather ironic, side to this coin would appear to be that

obese people, as suggested by their excellent appetites, are

potentially some of the very healthiest people with the longest life

expectancies, if only they could get control of their caloric intake.

Rodney.

[Guest guest]

Hi folks:

Notwithstanding what I said in my previous post, this paper does

raise the issue as to whether strength training (as opposed to

endurance exercise) may be very helpful to people on CRON.

It seems to me that for the most part the benefit from endurance

exercise is in reduction in CVD risk. So it may not do much to help

people on CRON. But if strength is independently associated with

longevity in people with CRON-type BMIs, then that is something we

(or at least I!) need to be persuaded about ...... by good

evidence, of course.

So I am 'all ears'.

Rodney.

>

> The study on grip strength and BMI seems to show that it is

important

> to be strong to survive. Last November, we discussed the paper by

> Calle[1] showing that the lowest mortality was associated with a BMI

> of 23.5 to 24.9 in men and 22.0 to 23.4 in women. Presumably the

> higher BMIs are associated with greater muscular strength, rather

than

> increased body fat.

>

> It seems that to live long, it is necessary to be slim enough to

avoid

> diabetes and CVD, but strong enough to be able to overcome the

> adversities that we face every day, like preventing falls. Muscular

> strength may also be indicative of other life-extending features,

> e.g., an improved immune system or improved metabolism.

>

> PMID: 15487904 suggests that athletic conditioning may increase

> maximal oxygen uptake, oxidative enzyme activities, and may also

have

> other positive changes in single muscle fiber size and metabolic

> properties.

>

> Minimizing BMI and neglecting strength-building exercises may not be

> the right strategy for human longevity.

>

> Tony

> ===

>

> ------- ----- grip strength -----

> ------- weaker - medium - stronger

> --BMI-- ------- -------- ---------

> --<20-- --136-- --127--- ---92----

> -20-25- --125-- --114--- --100----

> --25+-- --139-- --127--- --114----

>

>

> [1] Calle EE, Thun MJ, Petrelli JM, C, Heath CW

> Jr.

> Body-mass index and mortality in a prospective cohort

> of U.S. adults.

> N Engl J Med. 1999 Oct 7;341(15):1097-105.

> PMID: 10511607 http://tinyurl.com/k2jzg

> " In healthy people who had never smoked, the nadir of the curve for

> body-mass index and mortality was found at a body-mass index of 23.5

> to 24.9 in men and 22.0 to 23.4 in women. "

>

[Guest guest]

" Healthy, thin, nonsmoking people may not be at increased mortality

risk (41). In fact, people whose BMI was <20 and grip strength in the

highest tertile had a somewhat, though not significantly, lower

mortality risk than those with normal weight and grip strength in the

highest tertile. "

http://biomed.gerontologyjournals.org/cgi/content/full/55/3/M168?ijkey=a1908c156\

e62e792023b7ba17c39449b72d28fb2

DISCUSSION:

" Our study provides evidence that in a healthy population hand grip

strength measured during mid-life predicts risk of mortality from all

causes over a follow-up of 30 years, and its effect is independent of

BMI. Within all BMI categories, those in the lowest third of grip

strength had 20–39% greater risk than those in the highest third of

grip strength, as shown in Table 3 . Within individual grip strength

tertiles, BMI had much smaller and nonsignificant relationships with

mortality.

There are several potential mechanisms that may explain why mid-life

grip strength predicts long-term mortality. One explanation could be

earlier life influences that affect mid-life muscle strength. Good

strength could be an indicator of better childhood and early life

nutrition as those with better strength were taller. In addition,

mid-life strength may be modified by earlier life-style

characteristics, such as exercise habits; other factors such as type

of work; or early life diseases that have been cured but have had a

negative effect on strength (5)(20).

Secondly, poor muscle strength could be a risk factor for diseases or

an indicator of a subclinical disease. However, there is very little

information on whether strength predicts incident diseases, even

though poor muscle strength has been reported in people with chronic

conditions (2)(3)(4). Some evidence exists that poor strength precedes

the development of insulin resistance and predicts diabetes (21). Poor

muscle strength may be an etiologic factor in osteoarthritis (22).

Osteoarthritis causes pain and disability (23), and disability is

known to be a risk factor for mortality (24)(25). Disability and poor

muscle strength are often found in the same people (26), and good

muscle strength has been found to protect older people from

disability, independent of chronic diseases (27).

Thirdly, grip strength was associated with upper arm lean area and may

indicate a reserve of muscle mass which is important in cases of

trauma. After trauma, uninjured muscle goes into negative amino acid

balance, which facilitates gluconeogenesis in the liver to provide

glucose to damaged tissues. In addition, synthesis of antibodies and

cellular components is critical for survival in severe injury. If

muscle has been severely depleted by wasting, for example, due to

inactivity or aging, the amino acid reserve is low and the healing may

be compromised (13). For example, Griffith and colleagues found that

those who suffered postsurgery complication or died after the

operation had lower preoperative grip strength than those who showed

no complications after the surgery (28). However, the number of

subjects in that study was small (N = 55), and consequently the

differences did not yield statistical significance; also, the health

status before the surgery was not adjusted for. The importance of

protein reserve is also supported by a finding that moderately

overweight people more frequently survive hospitalization (29).

Fourthly, strength is associated with physical activity (10)(26),

which in itself predicts better survival (30)(31). We did adjust for

baseline physical activity, but the measure available was fairly crude

and may have not captured all of the variance in it.

It is worth noting that maximal voluntary muscle strength is

determined both by neural drive from motor cortex to muscles and

muscle mass (32)(33)(34)(35). Maximal voluntary strength is thus, in

fact, an indicator of the functioning of both the neural and the

muscular systems, and may be an overall indicator of a person's vigor.

Greater strength may mark some general intrinsic mid-life vitality or

stamina that tracks into survival into old age, and it may be a true

characteristic of the long-lived phenotype. There is a substantial

genetic component explaining the variability in muscle strength, with

heritability estimates varying between 30% and 79% (36)(37). Genes

that determine muscle strength are therefore possible candidate genes

for longevity.

The advantages of these analyses are that we had a healthy population

at baseline and a very long follow-up period. However, the limitation

of this study is that the Japanese-American male population studied

here is not representative of all older people. For example,

differences in muscle strength and body composition are known to exist

between men and women and between ethnic groups. From early adulthood

on, women have on average 30 to 40% less muscle strength than men

(38), yet they have longer average life expectancy than men. People of

Asian origin have lower BMI than Caucasian people, indicating lower

muscle mass (2). In addition, African Americans have been found to

have greater muscle strength (26), lean body mass, and muscle mass

than U.S. whites of the same weight and height (39)(40). It is obvious

that different populations or ethnic groups have strength

distributions that are shifted either lower (women) or higher (blacks)

than the distribution of the subjects of the current study. However,

it is unlikely that major racial or gender differences in the

strength-mortality relationship would be found. Nevertheless, these

analyses should be repeated in women and in populations consisting of

diverse racial groups.

Concluding that muscle strength is a more powerful predictor of

mortality than BMI may not be warranted on the basis of current data.

In this study, BMI alone showed only moderate effects on mortality.

About 10% greater mortality risk was observed in underweight and 11%

in overweight people as compared to persons with normal weight. The

moderate effect of BMI on mortality may partly be explained by the

fact that we removed from the analyses all subjects with documented

diseases at Exam 1, as well as all deaths that happened during the

first 3 years after Exam 1. Previously, in older populations, thin

people have been found to have greater mortality risk than normal

weight persons (11). However, it has been suggested that thin people

comprise a mix of those who are lean because they are physically

active, and those who are at greater mortality risk because they have

lost weight due to a sickness or who are thin because they smoke

tobacco (13)(41)(42). Healthy, thin, nonsmoking people may not be at

increased mortality risk (41). In fact, people whose BMI was <20 and

grip strength in the highest tertile had a somewhat, though not

significantly, lower mortality risk than those with normal weight and

grip strength in the highest tertile.

The unexpectedly flat mortality curve in the upper end of BMI could

also be partly explained by the fact that we removed all people with

cardiovascular diseases from the analyses. In addition, only 2.5% had

BMI >=30, indicating that this population had very few obese people

who might contribute to increased mortality in the high BMI group. In

a previous analysis on these data using the total population (N =

8006) without the exclusions done here, the relative risk of death

over 22 years of follow-up adjusted for age, smoking, and alcohol

consumption was 1.29 for the fifth quintile of BMI (BMI >26.30), with

the third quintile (BMI 23.01–24.60) as the reference group (43). In

our subsample of healthy people, overweight was not a strong predictor

of mortality. However, the same exclusions of high-risk men were true

for grip strength analyses, and yet a gradient of risk was evident in

the population included. When the analyses were carried out in the

total population, grip strength was even a stronger predictor of

mortality, because those who were sick at baseline had poorer strength

and were at increased risk of death.

In conclusion, we found that poor muscle strength measured in mid-life

predicts increased risk of all-cause mortality. Consequently,

increasing muscle strength by physical activity and strengthening

exercises in middle age may thus have a favorable impact on old age

morbidity and mortality. "

[Guest guest]

At 01:48 PM 2/22/2007, Rodney wrote:

>Hi folks:

>

>Notwithstanding what I said in my previous post, this paper does

>raise the issue as to whether strength training (as opposed to

>endurance exercise) may be very helpful to people on CRON.

Strength training does improve insulin sensitivity, which could

produce pro-longevity effects.

Essays Biochem. 2006;42:75-88. Resistance training, insulin

sensitivity and muscle function in the elderly. Dela F, Kjaer M.

Institute for Biomedical Sciences, University of Copenhagen, Denmark.

Ageing is associated with a loss in both muscle mass and in the

metabolic quality of skeletal muscle. This leads to sarcopenia and

reduced daily function, as well as to an increased risk for

development of insulin resistance and type 2 diabetes. A major part,

but not all, of these changes are associated with an age-related

decrease in the physical activity level and can be counteracted by

increased physical activity of a resistive nature. Strength training

has been shown to improve insulin-stimulated glucose uptake in both

healthy elderly individuals and patients with manifest diabetes, and

likewise to improve muscle strength in both elderly healthy

individuals and in elderly individuals with chronic disease. The

increased strength is coupled to improved function and a decreased

risk for fall injuries and fractures. Elderly individuals have

preserved the capacity to improve muscle strength and mass with

training, but seem to display a reduced sensitivity towards

stimulating protein synthesis from nutritional intake, rather than by

any reduced response in protein turnover to exercise.

Int J Med Sci. 2006 Dec 18;4(1):19-27. Strength training improves

muscle quality and insulin sensitivity in Hispanic older adults with

type 2 diabetes. N, Layne JE, Gordon PL, Roubenoff R,

ME, Castaneda-Sceppa C. 1. Mayer USDA Human Nutrition Research

Center on Aging, Tufts University, Boston MA, USA. Hispanics are at

increased risk of morbidity and mortality due to their high

prevalence of diabetes and poor glycemic control. Strength training

is the most effective lifestyle intervention to increase muscle mass

but limited data is available in older adults with diabetes. We

determined the influence of strength training on muscle quality

(strength per unit of muscle mass), skeletal muscle fiber

hypertrophy, and metabolic control including insulin resistance

(Homeostasis Model Assessment -HOMA-IR), C-Reactive Protein (CRP),

adiponectin and Free Fatty Acid (FFA) levels in Hispanic older

adults. Sixty-two community-dwelling Hispanics (>55 y) with type 2

diabetes were randomized to 16 weeks of strength training plus

standard care (ST group) or standard care alone (CON group). Skeletal

muscle biopsies and biochemical measures were taken at baseline and

16 weeks. The ST group show improved muscle quality (mean+/-SE:

28+/-3) vs CON (-4+/-2, p<0.001) and increased type I

(860+/-252microm(2)) and type II fiber cross-sectional area

(720+/-285microm(2)) compared to CON (type I: -164+/-290microm(2),

p=0.04; and type II: -130+/-336microm(2), p=0.04). This was

accompanied by reduced insulin resistance [sT: median (interquartile

range) -0.7(3.6) vs CON: 0.8(3.8), p=0.05]; FFA (ST:

-84+/-30micromol/L vs CON: 149+/-48micromol/L, p=0.02); and CRP [sT:

-1.3(2.9)mg/L vs CON: 0.4(2.3)mg/L, p=0.05]. Serum adiponectin

increased with ST [1.0(1.8)microg/mL] compared to CON

[-1.2(2.2)microg/mL, p<0.001]. Strength training improved muscle

quality and whole-body insulin sensitivity. Decreased inflammation

and increased adiponectin levels were related with improved metabolic

control. Further studies are needed to understand the mechanisms

associated with these findings. However, these data show that

strength training is an exercise modality to consider as an adjunct

of standard of care in high risk populations with type 2 diabetes.

Fadden

[Guest guest]

[cut for length]

> So, imo, those who 'naturally' have a BMI below 20 without having to > make an effort to achieve it are, often subclinically, sick. And the > majority of them will be malnourished also, either because of the > difficulties of obtaining the RDAs of nutrients at low intakes, or > because of a selective failure to absorb key nutrients. Intuition > suggests they would have higher mortality, and they are represented by > those shown to have BMI<20 and lower grip strength in that paper. > Those who are healthy, and manage to maintain a sensible BMI despite > the temptations to do otherwise, are represented by those with BMI<20 > and higher grip strength. And yes, we do not represent a high > percentage of the total population. The reason why in my post I > presented these data in tabular form was because, for me at least, it > makes the situation far clearer than when recited in the form of text.

Rodney and all,

I think your comments are spot-on. A perfect duo of examples is myself and my boyfriend. He has a BMI of about 19, and has the "stereotypical" programmer diet of no exercise whatsoever, tons of coffee, and an average of two meals daily usually consisting of cereal or a sandwich or crackers & cheese, followed by a meal of pasta with meat or a restaurant meal (also predominantly meat-starch). He is small & skinny and always has been, but is just beginning to start to show some belly fat, and realizes that this is all going to catch up with him, but doesn't seem to have motivation to actually act on that premonition.

Those of you that have met me know that I am thin/lean but not skinny, BMI of about 19-19.5, and a dedicated athlete. I run 6-7 hours per week and strength train 1-2 hours, somewhat constraining my ability to do "real" CR, but I definitely have the "ON" part nailed, to my satisfaction.

In a famine, who would go first, me or my boyfriend? Him probably by a nudge because I have more overall bodyfat. But when struck by illness or some kind of injury or physical impediment, I'd win by a mile.

[Guest guest]

>

> >Hi folks:

> >

> >Notwithstanding what I said in my previous post, this paper does

> >raise the issue as to whether strength training (as opposed to

> >endurance exercise) may be very helpful to people on CRON.

>

>

> Strength training does improve insulin sensitivity, which could

> produce pro-longevity effects.

>

> Essays Biochem. 2006;42:75-88. Resistance training, insulin

> sensitivity and muscle function in the elderly. Dela F, Kjaer M.

> Institute for Biomedical Sciences, University of Copenhagen,

Denmark.

[...snip...]

> Elderly individuals have

> preserved the capacity to improve muscle strength and mass with

> training, but seem to display a reduced sensitivity towards

> stimulating protein synthesis from nutritional intake, rather

> than by any reduced response in protein turnover to exercise.

OK, I read this last sentence about five times, and it's still

not making sense. Could someone please translate to lay-speak

please?

As a Bowflex user, I enjoy reading of the benefits of strength

training. They always seem tempered, however, by scary stuff

like this:

Unfavorable Effects of Resistance Training

on Central Arterial Compliance (2004)

http://circ.ahajournals.org/cgi/reprint/110/18/2858

This one seems more equivocal, with some good and maybe bad:

Endothelial function of young healthy males

following whole body resistance training (2005)

http://jap.physiology.org/cgi/reprint/98/6/2185

-

[Guest guest]

> > Elderly individuals have

> > preserved the capacity to improve muscle strength and mass with

> > training, but seem to display a reduced sensitivity towards

> > stimulating protein synthesis from nutritional intake, rather

> > than by any reduced response in protein turnover to exercise.

>

> OK, I read this last sentence about five times, and it's still

> not making sense. Could someone please translate to lay-speak

> please?

I have no medical qualifications of any kind, but my take on what that

passage is trying to say is as follows (with some extra added for

context):

Elderly people suffer from a reduction in both strength and muscle

mass (including what is called sarcopenia), and this can cause all

kinds of problems. But muscle mass can to some extent be preserved in

the elderly by appropriate exercise. However, the major problem

elderly people have with muscle mass is not so much that their muscles

are unwilling to respond to exercise, but rather that their bodies are

unable to transform the protein they get from food into the protein

required for restoration of muscle mass.

Just my take. May not be correct, of course.

Rodney.