The influence of resistance and aerobic exercise on hunger

[Guest guest]

The below may be of interest:

Exercise suppresses appetite by affecting appetite hormones

http://esciencenews.com/articles/2008/12/11/exercise.suppresses.appeti

te.affecting.appetite.hormones

BETHESDA, Md. (Dec. 11, 2008) & #8722; A vigorous 60-minute workout on a

treadmill affects the release of two key appetite hormones, ghrelin

and peptide YY, while 90 minutes of weight lifting affects the level

of only ghrelin, according to a new study. Taken together, the

research shows that aerobic exercise is better at suppressing

appetite than non-aerobic exercise and provides a possible

explanation for how that happens.

Treadmill versus weight lifting

There are several hormones that help regulate appetite, but the

researchers looked at two of the major ones, ghrelin and peptide YY.

Ghrelin is the only hormone known to stimulate appetite. Peptide YY

suppresses appetite.

Ghrelin was discovered by researchers in Japan only about 10 years

ago and was originally identified for its role as a growth hormone.

Only later did its role in stimulating appetite become known. Peptide

YY was discovered less than 25 years ago.

In this experiment, 11 male university students did three eight-hour

sessions. During one session they ran for 60 minutes on a treadmill,

and then rested for seven hours. During another session they did 90

minutes of weight lifting, and then rested for six hours and 30

minutes. During another session, the participants did not exercise at

all.

During each of the sessions, the participants filled out surveys in

which they rated how hungry they felt at various points. They also

received two meals during each session. The researchers measured

ghrelin and peptide YY levels at multiple points along the way.

They found that the treadmill (aerobic) session caused ghrelin levels

to drop and peptide YY levels to increase, indicating the hormones

were suppressing appetite. However, a weight-lifting (non-aerobic)

session produced a mixed result. Ghrelin levels dropped, indicating

appetite suppression, but peptide YY levels did not change

significantly.

Based on the hunger ratings the participants filled out, both aerobic

and resistance exercise suppressed hunger, but aerobic exercise

produced a greater suppression of hunger. The changes the researchers

observed were short term for both types of exercise, lasting about

two hours, including the time spent exercising, Stensel reported.

" The finding that hunger is suppressed during and immediately after

vigorous treadmill running is consistent with previous studies

indicating that strenuous aerobic exercise transiently suppresses

appetite, " Stensel said. " The findings suggest a similar, although

slightly attenuated response, for weight lifting exercise. "

Focus on active ghrelin

Previous studies have been inconclusive about whether exercise

decreases ghrelin levels, but this study may help explain those mixed

results, according to the researchers.

Ghrelin comes in two forms, acylated and non-acylated. The

researchers measured acylated ghrelin, also called active ghrelin,

because it can cross the blood-brain barrier and reach the appetite

center in the brain. Stensel suggests that future research

concentrate on active ghrelin.

While the study showed that exercise suppresses appetite hormones,

the next step is to establish whether this change actually causes the

suppression of eating.

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

Carruthers

Wakefield, UK

[Guest guest]

Exercise suppresses appetite by affecting appetite hormones

This is a very interesting article which surely will provoke multiple postings

either downplaying its relevance (resistance advocates) or extolling its

findings (aerobic advocates).

As with any study, before accepting its conclusions and proclaiming it is proof

positive that it upholds your beliefs, it is important to look at the study

very closely and evaluating it.

There are several important points that I noted and would like to point out.

- The authors conclusions-

*************************

" While the study showed that exercise suppresses appetite hormones, 
the next

step is to establish whether this change actually causes the 
suppression of

eating. "

*************************

The authors caution that further studies need to be done to see what effect

this change in hormones has on the overall calorie intake is over time (24 hrs).

Flaws in the study-

A common flaw I find in this and many studies comparing resistance training vs

aerobic training is that of trying to compare apples to oranges.

The authors describe the aerobic activity as vigorous but don't describe the

intensity of the resistance activity.

What does that mean? Unless we can compare the total energy (or power) output

during each session, as well the different energy substrates (fat vs glucose)

used by the athletes in each exercise session (aerobic vs resistance) how can

we say that the sessions are equivalent and therefore the elicited response is

valid for comparison. If the intensity and/or workout put is not equivalent

there may not be an equivalent hormone response.

Substrate utilization may also be important. If the aerobic session utilized

more fat substrate than glucose and the resistance utilized more glucose

substrate than fat the hormonal response for each might in fact be different.

Overall I found the study to be interesting and I am sure the authors have

several other studies in the works to better clarify what the initial findings

mean.

Ralph Giarnella MD

Southington Ct USA

>

> Subject: The influence of resistance and aerobic exercise on

hunger

> To: Supertraining

> Date: Saturday, December 13, 2008, 8:16 AM

> The below may be of interest:

>

> Exercise suppresses appetite by affecting appetite hormones

>

> http://esciencenews.com/articles/2008/12/11/exercise.suppresses.appeti

> te.affecting.appetite.hormones

>

> BETHESDA, Md. (Dec. 11, 2008) & #8722; A vigorous

> 60-minute workout on a

> treadmill affects the release of two key appetite hormones,

> ghrelin

> and peptide YY, while 90 minutes of weight lifting affects

> the level

> of only ghrelin, according to a new study. Taken together,

> the

> research shows that aerobic exercise is better at

> suppressing

> appetite than non-aerobic exercise and provides a possible

> explanation for how that happens.

>

> Treadmill versus weight lifting

> There are several hormones that help regulate appetite, but

> the

> researchers looked at two of the major ones, ghrelin and

> peptide YY.

> Ghrelin is the only hormone known to stimulate appetite.

> Peptide YY

> suppresses appetite.

>

> Ghrelin was discovered by researchers in Japan only about

> 10 years

> ago and was originally identified for its role as a growth

> hormone.

> Only later did its role in stimulating appetite become

> known. Peptide

> YY was discovered less than 25 years ago.

>

> In this experiment, 11 male university students did three

> eight-hour

> sessions. During one session they ran for 60 minutes on a

> treadmill,

> and then rested for seven hours. During another session

> they did 90

> minutes of weight lifting, and then rested for six hours

> and 30

> minutes. During another session, the participants did not

> exercise at

> all.

>

> During each of the sessions, the participants filled out

> surveys in

> which they rated how hungry they felt at various points.

> They also

> received two meals during each session. The researchers

> measured

> ghrelin and peptide YY levels at multiple points along the

> way.

> They found that the treadmill (aerobic) session caused

> ghrelin levels

> to drop and peptide YY levels to increase, indicating the

> hormones

> were suppressing appetite. However, a weight-lifting

> (non-aerobic)

> session produced a mixed result. Ghrelin levels dropped,

> indicating

> appetite suppression, but peptide YY levels did not change

> significantly.

>

> Based on the hunger ratings the participants filled out,

> both aerobic

> and resistance exercise suppressed hunger, but aerobic

> exercise

> produced a greater suppression of hunger. The changes the

> researchers

> observed were short term for both types of exercise,

> lasting about

> two hours, including the time spent exercising, Stensel

> reported.

> " The finding that hunger is suppressed during and

> immediately after

> vigorous treadmill running is consistent with previous

> studies

> indicating that strenuous aerobic exercise transiently

> suppresses

> appetite, " Stensel said. " The findings suggest a

> similar, although

> slightly attenuated response, for weight lifting

> exercise. "

>

> Focus on active ghrelin

> Previous studies have been inconclusive about whether

> exercise

> decreases ghrelin levels, but this study may help explain

> those mixed

> results, according to the researchers.

> Ghrelin comes in two forms, acylated and non-acylated. The

> researchers measured acylated ghrelin, also called active

> ghrelin,

> because it can cross the blood-brain barrier and reach the

> appetite

> center in the brain. Stensel suggests that future research

> concentrate on active ghrelin.

> While the study showed that exercise suppresses appetite

> hormones,

> the next step is to establish whether this change actually

> causes the

> suppression of eating.

>

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

> Carruthers

> Wakefield, UK

[Guest guest]

>

> Exercise suppresses appetite by affecting appetite hormones

>

> This is a very interesting article which surely will provoke

multiple postings either downplaying its relevance (resistance

advocates) or extolling its findings (aerobic advocates).

> As with any study, before accepting its conclusions and proclaiming

it is proof positive that it upholds your beliefs, it is important

to look at the study very closely and evaluating it.

> There are several important points that I noted and would like to

point out.

> - The authors conclusions-

> *************************

> " While the study showed that exercise suppresses appetite hormones,


the next step is to establish whether this change actually causes

the 
suppression of eating. "

> *************************

> The authors caution that further studies need to be done to see

what effect this change in hormones has on the overall calorie intake

is over time (24 hrs).

>

> Flaws in the study-

> A common flaw I find in this and many studies comparing resistance

training vs aerobic training is that of trying to compare apples to

oranges.

> The authors describe the aerobic activity as vigorous but don't

describe the intensity of the resistance activity.

> What does that mean? Unless we can compare the total energy (or

power) output during each session, as well the different energy

substrates (fat vs glucose) used by the athletes in each exercise

session (aerobic vs resistance) how can we say that the sessions are

equivalent and therefore the elicited response is valid for

comparison. If the intensity and/or workout put is not equivalent

there may not be an equivalent hormone response.

> Substrate utilization may also be important. If the aerobic

session utilized more fat substrate than glucose and the resistance

utilized more glucose substrate than fat the hormonal response for

each might in fact be different.

>

> Overall I found the study to be interesting and I am sure the

authors have several other studies in the works to better clarify

what the initial findings mean.

>

*********

The full article can be found at:

http://ajpregu.physiology.org/cgi/reprint/90706.2008v1?maxtoshow= & HITS=10 & hits=1\

0 & RESULTFORMAT= & author1=Stensel+ & andorexactfulltext=and & searchid=1 & FIRSTINDEX=0 & \

sortspec=relevance & resourcetype=HWCIT

Aerobic exercise trial. At the start of this trial participants ran

on the treadmill for 60 min at a speed predicted to elicit 70% of

maximum oxygen uptake. One minute expired air samples were collected

into bags at 14-15, 29- 30, 44-45 and 59-60 min during the

run. Oxygen consumption and carbon dioxide production were determined

from expired air samples as described previously (9). Energy

expenditure was predicted from oxygen consumption and carbon dioxide

production values using indirect calorimetry (20). Ratings of

perceived exertion were recorded during each expired air collection

using the Borg scale (8). After the run, participants rested for 7 h.

[: Weightlifting?!]

Weight lifting tests. A 12-repetition maximum test was completed for

each of the 10 resistance exercises employed in the study. The order

in which each exercise was performed was: squat, dumbbell lateral

raise, bench press, upright row, lunges, bicep curl, barbell

pullover, seated shoulder press, triceps extension and bent over

row. On a separate visit subjects undertook a 90 min familiarisation

session where they completed a full weight lifting session: three sets

of 12 repetitions of 10 different weight lifting exercises at 80% of

12 repetition max.

The total weight lifted during the 90 min resistance exercise session

was 10,568 & #61617; & #61472;621 kg. The gross energy expenditure from resistance

exercise was estimated to be 1473 & #61617; & #61472;114 kJ. The mean percentage of

maximum oxygen uptake elicited during aerobic exercise was 69 & #61617; & #61472;2%

and the mean respiratory exchange ratio (RER) was 0.92 & #61617; & #61472;0.01.

Average heart rate during running was 167 & #61617; & #61472;3 beats/min and the

median rating of perceived exertion (RPE) was 15 i.e. hard' (range 13-17).

Gross energy expenditure during aerobic exercise was 3832 & #61617; & #61472;97 kJ

with

27 & #61617; & #61472;4% of energy provided from fat and 73 & #61617; 4% of energy

provided

from carbohydrate. For comparison gross energy expenditure during the

first hour of the control trial was 363 & #61617; & #61472;24 kJ, the mean RER

value

during this time was 0.84 & #61617; 0.03 with 47 & #61617; & #61472;11% of energy

provided

from fat and 53 & #61617; & #61472;4% of energy provided from carbohydrate. Energy

expenditure during running was higher than energy expenditure in

resistance exercise which in turn was higher than energy expenditure

during an equivalent (90 min) period of rest during the control trial

(P<0.0005 for each).

The finding that hunger is suppressed during and immediately after

vigorous treadmill running is consistent with previous studies

indicating that strenuous (around 60% of maximum oxygen uptake and

above) aerobic exercise transiently suppresses appetite (6, 9, 29,

39). The hunger response to resistance exercise has not

previously been examined and the present findings suggest a similar

although slightly attenuated response in comparison with vigorous

running. One possible explanation for this attenuation is the lower

energy expenditure during resistance exercise. Another possibility is

that the attenuated responses are due to the intermittent nature of

resistance exercise and the lower gut disturbance compared with

running.

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

Carruthers

Wakefield, UK

[Guest guest]

Thank you for supplying the full article. That answers some of my

questions.

Ralph Giarnella MD

Southington Ct USA

>

> Subject: Re: The influence of resistance and aerobic exercise

on hunger

> To: Supertraining

> Date: Saturday, December 13, 2008, 11:21 AM

>

> >

> > Exercise suppresses appetite by affecting appetite

> hormones

> >

> > This is a very interesting article which surely will

> provoke

> multiple postings either downplaying its relevance

> (resistance

> advocates) or extolling its findings (aerobic advocates).

> > As with any study, before accepting its conclusions

> and proclaiming

> it is proof positive that it upholds your beliefs, it is

> important

> to look at the study very closely and evaluating it.

> > There are several important points that I noted and

> would like to

> point out.

> > - The authors conclusions-

> > *************************

> > " While the study showed that exercise suppresses

> appetite hormones,

> 
the next step is to establish whether this change

> actually causes

> the 
suppression of eating. "

> > *************************

> > The authors caution that further studies need to be

> done to see

> what effect this change in hormones has on the overall

> calorie intake

> is over time (24 hrs).

> >

> > Flaws in the study-

> > A common flaw I find in this and many studies

> comparing resistance

> training vs aerobic training is that of trying to compare

> apples to

> oranges.

> > The authors describe the aerobic activity as vigorous

> but don't

> describe the intensity of the resistance activity.

> > What does that mean? Unless we can compare the total

> energy (or

> power) output during each session, as well the different

> energy

> substrates (fat vs glucose) used by the athletes in each

> exercise

> session (aerobic vs resistance) how can we say that the

> sessions are

> equivalent and therefore the elicited response is valid for

> comparison. If the intensity and/or workout put is not

> equivalent

> there may not be an equivalent hormone response.

> > Substrate utilization may also be important. If the

> aerobic

> session utilized more fat substrate than glucose and the

> resistance

> utilized more glucose substrate than fat the hormonal

> response for

> each might in fact be different.

> >

> > Overall I found the study to be interesting and I am

> sure the

> authors have several other studies in the works to better

> clarify

> what the initial findings mean.

> >

>

> *********

> The full article can be found at:

>

http://ajpregu.physiology.org/cgi/reprint/90706.2008v1?maxtoshow= & HITS=10 & hits=1\

0 & RESULTFORMAT= & author1=Stensel+ & andorexactfulltext=and & searchid=1 & FIRSTINDEX=0 & \

sortspec=relevance & resourcetype=HWCIT

>

> Aerobic exercise trial. At the start of this trial

> participants ran

> on the treadmill for 60 min at a speed predicted to elicit

> 70% of

> maximum oxygen uptake. One minute expired air samples were

> collected

> into bags at 14-15, 29- 30, 44-45 and 59-60 min

> during the

> run. Oxygen consumption and carbon dioxide production were

> determined

> from expired air samples as described previously (9).

> Energy

> expenditure was predicted from oxygen consumption and

> carbon dioxide

> production values using indirect calorimetry (20). Ratings

> of

> perceived exertion were recorded during each expired air

> collection

> using the Borg scale (8). After the run, participants

> rested for 7 h.

>

> [: Weightlifting?!]

> Weight lifting tests. A 12-repetition maximum test was

> completed for

> each of the 10 resistance exercises employed in the study.

> The order

> in which each exercise was performed was: squat, dumbbell

> lateral

> raise, bench press, upright row, lunges, bicep curl,

> barbell

> pullover, seated shoulder press, triceps extension and bent

> over

> row. On a separate visit subjects undertook a 90 min

> familiarisation

> session where they completed a full weight lifting session:

> three sets

> of 12 repetitions of 10 different weight lifting exercises

> at 80% of

> 12 repetition max.

>

> The total weight lifted during the 90 min resistance

> exercise session

> was 10,568 & #61617; & #61472;621 kg. The gross energy

> expenditure from resistance exercise was estimated to be

> 1473 & #61617; & #61472;114 kJ. The mean percentage of

> maximum oxygen uptake elicited during aerobic exercise was

> 69 & #61617; & #61472;2% and the mean respiratory

> exchange ratio (RER) was 0.92 & #61617; & #61472;0.01.

> Average heart rate during running was 167

> & #61617; & #61472;3 beats/min and the median rating of

> perceived exertion (RPE) was 15 i.e. hard' (range

> 13-17).

>

> Gross energy expenditure during aerobic exercise was 3832

> & #61617; & #61472;97 kJ with

> 27 & #61617; & #61472;4% of energy provided from fat

> and 73 & #61617; 4% of energy provided

> from carbohydrate. For comparison gross energy expenditure

> during the

> first hour of the control trial was 363

> & #61617; & #61472;24 kJ, the mean RER value

> during this time was 0.84 & #61617; 0.03 with 47

> & #61617; & #61472;11% of energy provided

> from fat and 53 & #61617; & #61472;4% of energy

> provided from carbohydrate. Energy

> expenditure during running was higher than energy

> expenditure in

> resistance exercise which in turn was higher than energy

> expenditure

> during an equivalent (90 min) period of rest during the

> control trial

> (P<0.0005 for each).

>

> The finding that hunger is suppressed during and

> immediately after

> vigorous treadmill running is consistent with previous

> studies

> indicating that strenuous (around 60% of maximum oxygen

> uptake and

> above) aerobic exercise transiently suppresses appetite (6,

> 9, 29,

> 39). The hunger response to resistance exercise has not

> previously been examined and the present findings suggest a

> similar

> although slightly attenuated response in comparison with

> vigorous

> running. One possible explanation for this attenuation is

> the lower

> energy expenditure during resistance exercise. Another

> possibility is

> that the attenuated responses are due to the intermittent

> nature of

> resistance exercise and the lower gut disturbance compared

> with

> running.

>

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

> Carruthers

> Wakefield, UK

[Guest guest]

>

> I just swam for an hour. I'm starving. I'm always starving after

swimming. So, it's not just any " aerobic " exercise.

>

> I'm sure the not-weight-bearing nature of swimming is a factor.

Possibly internal body temperature is a factor with swimming being

lower due to the cooling of the water. I have no idea how close to

70% of maximum oxygen uptake I am. I'm just glad to get enough air

to keep swimming.

>

****

Interestingly we discussed the latter some years ago, here are two

relevant contributions:

There tends to be a considerable loss in heat during swimming

(especially in cold water) through conduction and convection

approximately 25 times greater compared to a similar air temperature.

As a result, core temperature while swimming does not rise to the

same degree as it does when running, jogging, cycling etc. An

increase in body temp tends to suppress appetite to a certain degree,

hence the reason for not feeling that hungry after jogging / biking.

Have a look through the message board as well and research papers by

Costill et al., and Gwinup.

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

I agree with Mr. Carruthers that the answer lies with heat loss.

However, while it is possible that increased body temperature cold

supress hunger (I am not familiar with this research), I believe the

answer has more to do with an increase in appetite in the (cold)

water, rather than a decrease in appetite during " warm " exercise.

The largest interindividual variable pertaining to heat loss while

swimming is %BF. For some fatter individuals, swimming in fairly

warm water > 30 degrees Celsius, it is possible that their

subcutaneous insulation, coupled with the peripheral vasoconstriction

response, will maintain their core temperature reasonably well,

without shivering.

However, for thinner individuals, (particularly for males with %BF

below 10 - 12 %), the lack of a thermally insulative fat layer

necessitates vigorous shivering, or at the very least, increased

muscle tonus (i.e. cocontraction). Shivering thermogenesis is fueled

in large part by fat oxidation, but intramuscular glycogen also plays

a significant role (plasma glucose is also involved to some degree).

Depletion of these substrates (particularly the intramuscular

glycogen and the plasma glucose) leads to hunger following your swim.

You may also notice that swimming has a strong diuretic effect. Part

of this has to do with the depletion of hepatic and intramuscular

glycogen, since it takes 3 g of water to solvate 1 g of

glycogen...but the most significant reason for the diuresis is that

the increased pressure induced by water submersion (coupled with the

peripheral vasoconstriction response) causes the blood to

be " squeezed " from the periphery into the trunk. The resulting

central venous pressure " overload " signals the kidneys to reduce

blood volume by secreting more water into the bladder.

The research literature by Shepherd, Vallerand, s, eau,

Tikuisis, and more recently, Haman may be helpful if anyone is

interested in more information about thermoregulation during water

immersion / swimming activity.

- Lounsbury

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

Carruthers

Wakefield, UK

> The influence of resistance and aerobic

exercise on hunger

>

>

> The below may be of interest:

>

> Exercise suppresses appetite by affecting appetite hormones

>

>

http://esciencenews.com/articles/2008/12/11/exercise.suppresses.appeti

> te.affecting.appetite.hormones

>

> BETHESDA, Md. (Dec. 11, 2008) & #8722; A vigorous 60-minute

workout on a

> treadmill affects the release of two key appetite hormones,

ghrelin

> and peptide YY, while 90 minutes of weight lifting affects the

level

> of only ghrelin, according to a new study. Taken together, the

> research shows that aerobic exercise is better at suppressing

> appetite than non-aerobic exercise and provides a possible

> explanation for how that happens.

>

> Treadmill versus weight lifting

> There are several hormones that help regulate appetite, but the

> researchers looked at two of the major ones, ghrelin and peptide

YY.

> Ghrelin is the only hormone known to stimulate appetite. Peptide

YY

> suppresses appetite.

>

> Ghrelin was discovered by researchers in Japan only about 10

years

> ago and was originally identified for its role as a growth

hormone.

> Only later did its role in stimulating appetite become known.

Peptide

> YY was discovered less than 25 years ago.

>

> In this experiment, 11 male university students did three eight-

hour

> sessions. During one session they ran for 60 minutes on a

treadmill,

> and then rested for seven hours. During another session they did

90

> minutes of weight lifting, and then rested for six hours and 30

> minutes. During another session, the participants did not

exercise at

> all.

>

> During each of the sessions, the participants filled out surveys

in

> which they rated how hungry they felt at various points. They

also

> received two meals during each session. The researchers measured

> ghrelin and peptide YY levels at multiple points along the way.

> They found that the treadmill (aerobic) session caused ghrelin

levels

> to drop and peptide YY levels to increase, indicating the

hormones

> were suppressing appetite. However, a weight-lifting (non-

aerobic)

> session produced a mixed result. Ghrelin levels dropped,

indicating

> appetite suppression, but peptide YY levels did not change

> significantly.

>

> Based on the hunger ratings the participants filled out, both

aerobic

> and resistance exercise suppressed hunger, but aerobic exercise

> produced a greater suppression of hunger. The changes the

researchers

> observed were short term for both types of exercise, lasting

about

> two hours, including the time spent exercising, Stensel reported.

> " The finding that hunger is suppressed during and immediately

after

> vigorous treadmill running is consistent with previous studies

> indicating that strenuous aerobic exercise transiently suppresses

> appetite, " Stensel said. " The findings suggest a similar,

although

> slightly attenuated response, for weight lifting exercise. "

>

> Focus on active ghrelin

> Previous studies have been inconclusive about whether exercise

> decreases ghrelin levels, but this study may help explain those

mixed

> results, according to the researchers.

> Ghrelin comes in two forms, acylated and non-acylated. The

> researchers measured acylated ghrelin, also called active

ghrelin,

> because it can cross the blood-brain barrier and reach the

appetite

> center in the brain. Stensel suggests that future research

> concentrate on active ghrelin.

> While the study showed that exercise suppresses appetite

hormones,

> the next step is to establish whether this change actually causes

the

> suppression of eating.

>

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

>