Overweight people won't gain anything going from 30

PercivalHackworth

A quite interesting study : doing 60 minutes of cardio doesn't burn more fat than 30 minutes for overweight people, it seems to exist a limit to the amount one can burn fat. With athletes you only increase chances of protein catabolism with too much cardio

Body fat loss and compensatory mechanisms in response to different doses of aerobic exercise—a randomized controlled trial in overweight sedentary males
Mads Rosenkilde AJP - Regu Physiol September 15, 2012 vol. 303 no. 6 R571-R579

The amount of weight loss induced by exercise is often disappointing. A diet-induced negative energy balance triggers compensatory mechanisms, e.g., lower metabolic rate and increased appetite. However, knowledge about potential compensatory mechanisms triggered by increased aerobic exercise is limited.

A randomized controlled trial was performed in healthy, sedentary, moderately overweight young men to examine the effects of increasing doses of aerobic exercise on body composition, accumulated energy balance, and the degree of compensation. Eighteen participants were randomized to a continuous sedentary control group, 21 to a moderate-exercise (MOD; 300 kcal/day), and 22 to a high-exercise (HIGH; 600 kcal/day) group for 13 wk, corresponding to ∼30 and 60 min of daily aerobic exercise, respectively.

Body weight (MOD: −3.6 kg, P < 0.001; HIGH: −2.7 kg, P = 0.01) and fat mass (MOD: −4.0 kg, P < 0.001 and HIGH: −3.8 kg, P < 0.001) decreased similarly in both exercise groups. Although the exercise-induced energy expenditure in HIGH was twice that of MOD, the resulting accumulated energy balance, calculated from changes in body composition, was not different (MOD: −39.6 Mcal, HIGH: −34.3 Mcal, not significant). Energy balance was 83% more negative than expected in MOD, while it was 20% less negative than expected in HIGH. No statistically significant changes were found in energy intake or nonexercise physical activity that could explain the different compensatory responses associated with 30 vs. 60 min of daily aerobic exercise. In conclusion, a similar body fat loss was obtained regardless of exercise dose.

A moderate dose of exercise induced a markedly greater than expected negative energy balance, while a higher dose induced a small but quantifiable degree of compensation.

URL :
http://www.ncbi.nlm.nih.gov/pubmed/22855277

TheNewDodge

Caloric deficits

djkshdfd

Interesting. Thanks buddy!

Lleldiranne

Interesting. I am assuming that this is the abstract? (The basic big idea of the study without all the details).

Anyway, it only addresses fat/weight loss among overweight. It says nothing about well-conditioned athletes, so your assumption that you increase chances of protein catabolism are unsupported (at least as far as the abstract … and it suggests nothing about looking at that). They also didn't include any resistance training, which could change matters. So I will continue to exercise at the levels I have been, 45-60 minutes most days, because I am doing it for more than just weight loss, I am doing it for overall health, which wasn't tested by this study (and the "small but quantifiable degree of compensation" suggests that while 60 minutes is only slightly more effective than 30, it still has differences).

TheNewDodge - the did rule out Caloric deficits: "No statistically significant changes were found in energy intake or nonexercise physical activity that could explain the different compensatory responses associated with 30 vs. 60 min of daily aerobic exercise."

neverstray

I learned about 5 years ago that about 20 to 30 minutes of HITT is ideal for fat burning. Anymore than that, and it starts moving from fat burning to a different mode in the body, I forget what it's called. But, the body cannot physically burn anymore fat after about 30 minutes.

Most fat burning is done in the kitchen by not eating it.

Helloitsdan

Raz this falls in line with Martins paper on how the body thinks it should lose weight.
Awesome stuff!

Heres the article if you guys want to read....
https://www.facebook.com/notes/leangains/the-logics-of-weight-loss-how-your-body-thinks-it-should-be-done/160054937436250

People think i'm crazy when I tell them you can Break a plateau or lose more weight with moderate exercise 3-4x a week.
Science is fun!
=D

ilovedeadlifts

I just do HIIT.


But when I did longer sessions, it was for the purpose of creating a caloric deficit not "fat burning".

emnk5308

I just do HIIT.


But when I did longer sessions, it was for the purpose of creating a caloric deficit not "fat burning".

What is this? I've heard of it before but don't understand.. :embarassed:

ChitownFoodie

I just do HIIT.


But when I did longer sessions, it was for the purpose of creating a caloric deficit not "fat burning".

I do the same! I don't think I burn fat anymore. It's sort of sad in a way.

Erisad

I learned about 5 years ago that about 20 to 30 minutes of HITT is ideal for fat burning. Anymore than that, and it starts moving from fat burning to a different mode in the body, I forget what it's called. But, the body cannot physically burn anymore fat after about 30 minutes.

Most fat burning is done in the kitchen by not eating it.

I heard this too. I just up the intensity and I'm seeing better results than when I'd go longer on a lower intensity.

LNZimmer

bump...

at work and i can't really read this stuff right now! but want to!

Yanicka1

bump

myofibril

The obvious question here is how the participants diet was monitored and if it was held constant between the three groups.

If it was self reported, free living conditions then this study doesn't tell us a huge amount other than doing exercise for "fat burn" rather than creating a calorie deficit is a bit rubbish. Which we already know.

To be conclusive an exercise study really needs to be in controlled, clinical environment where dietary intake is rigorously controlled. Otherwise you get people like Taubes banging on about how useless aerobic exercise is for changing body composition which makes me want to punch things.

On a brighter note punching things is good for creating a calorie deficit....

McBully4

But when I did longer sessions, it was for the purpose of creating a caloric deficit not "fat burning".

^^
this

Like others said, you have more control over fat in the kitchen

icimani

Really small study, but interesting results.

auroranflash

Raz this falls in line with Martins paper on how the body thinks it should lose weight.
Awesome stuff!

Heres the article if you guys want to read....
https://www.facebook.com/notes/leangains/the-logics-of-weight-loss-how-your-body-thinks-it-should-be-done/160054937436250

People think i'm crazy when I tell them you can Break a plateau or lose more weight with moderate exercise 3-4x a week.
Science is fun!
=D

Interesting read, Dan. Thanks.

LowcarbNY

Conclusion: Get some aerobic exercise every day, don't try to do it all on the weekend.

PaulW2MD

Interesting, Thanks.

spinqueen72

I just do HIIT.


But when I did longer sessions, it was for the purpose of creating a caloric deficit not "fat burning".

What is this? I've heard of it before but don't understand.. :embarassed:

It is High Intense Interval Training
You put your body through short bursts of intense physical exertion...with small resting periods in between. It helps to confuse the muscles, and revs up the metabolism & heart rate very quickly!

jdploki70

Really small study, but interesting results.

Yeah, as far as the abstract goes, the n (that is the sample size) is relatively low to not rule out other factors. The fact that all the participants were relatively young tells me that it was likely a study done at a university with the subjects being students. As a college student I already did a good 30-60 minutes of aerobic exercise just getting to class on time. In order for this to be a more valid study, the experiment should be repeated in a controlled environment. All activity, not just that on the stationary bike, has to be accounted for, as well as all dietary intakes and it needs to be conducted across both genders and across a larger age group.

Interesting study, but more research is needed for this to be definitive in any respect.

yarwell

Caloric deficits

http://ajpregu.physiology.org/content/303/6/R571.full

"Eighteen participants were randomized to a continuous sedentary control group, 21 to a moderate-exercise (MOD; 300 kcal/day), and 22 to a high-exercise (HIGH; 600 kcal/day) group for 13 wk, corresponding to ∼30 and 60 min of daily aerobic exercise, respectively. "

"Although the exercise-induced energy expenditure in HIGH was twice that of MOD, the resulting accumulated energy balance, calculated from changes in body composition, was not different (MOD: −39.6 Mcal, HIGH: −34.3 Mcal, not significant). Energy balance was 83% more negative than expected in MOD, while it was 20% less negative than expected in HIGH. No statistically significant changes were found in energy intake or nonexercise physical activity that could explain the different compensatory responses associated with 30 vs. 60 min of daily aerobic exercise. In conclusion, a similar body fat loss was obtained regardless of exercise dose."

Helloitsdan

Caloric deficits

http://ajpregu.physiology.org/content/303/6/R571.full

"Eighteen participants were randomized to a continuous sedentary control group, 21 to a moderate-exercise (MOD; 300 kcal/day), and 22 to a high-exercise (HIGH; 600 kcal/day) group for 13 wk, corresponding to ∼30 and 60 min of daily aerobic exercise, respectively. "

"Although the exercise-induced energy expenditure in HIGH was twice that of MOD, the resulting accumulated energy balance, calculated from changes in body composition, was not different (MOD: −39.6 Mcal, HIGH: −34.3 Mcal, not significant). Energy balance was 83% more negative than expected in MOD, while it was 20% less negative than expected in HIGH. No statistically significant changes were found in energy intake or nonexercise physical activity that could explain the different compensatory responses associated with 30 vs. 60 min of daily aerobic exercise. In conclusion, a similar body fat loss was obtained regardless of exercise dose."

Excellent!

myofibril

http://ajpregu.physiology.org/content/303/6/R571.full

"Eighteen participants were randomized to a continuous sedentary control group, 21 to a moderate-exercise (MOD; 300 kcal/day), and 22 to a high-exercise (HIGH; 600 kcal/day) group for 13 wk, corresponding to ∼30 and 60 min of daily aerobic exercise, respectively. "

"Although the exercise-induced energy expenditure in HIGH was twice that of MOD, the resulting accumulated energy balance, calculated from changes in body composition, was not different (MOD: −39.6 Mcal, HIGH: −34.3 Mcal, not significant). Energy balance was 83% more negative than expected in MOD, while it was 20% less negative than expected in HIGH. No statistically significant changes were found in energy intake or nonexercise physical activity that could explain the different compensatory responses associated with 30 vs. 60 min of daily aerobic exercise. In conclusion, a similar body fat loss was obtained regardless of exercise dose."

Thanks for providing the full study link. That is helpful.

As everyone will note:

Habitual EI was calculated from food records on the same weekdays at baseline and in week 11. All subjects were told to carefully weigh and record all foods and drinks consumed for 3 days. The recordings were processed using appropriate software (Dankost 3000; Dankost, Copenhagen, Denmark).

and

Diets were provided to the subjects for ad libitum consumption during an 8-day period at baseline and at the 13th week

and

Subjects were instructed to select freely from the food items provided and to eat until comfortably satiated. All leftovers were returned and weighed, and energy intake was subsequently calculated. Ad libitum EI during the last 3 days of each feeding regimen and pooled data from all 8 diet days were analyzed.

Do I really need to spell this out....

DLKeeble

bump

GauchoMark

interesting study, but I don't buy it. Too many holes.

Probably the worst one is the sample size - they do a sample size calculation to see how many people they need to be able to detect a 25% change in body fat that says they need 20 people. They stop the test at a max group change of 14% and only have 17-18 people. So, essentially, by their OWN calculations, they don't have enough people to be able to detect any meaningful change anyways.

There are a lot of other problems with this experiment too. Even though they may be right, they didn't prove anything - complete waste of time and resources.

dap1217

bump

yarwell

Do I really need to spell this out....

Yeah, give us your explanation of the lack of difference in weight loss. Is it a Taubes like "exercise makes you hungry" so the high exercise group ate more ? The authors were leaning that way "there is some indication that EI increased in HIGH, driving the small but quantifiable degree of compensation"

There was a bigger increase in non-exercise activity in the MODerate exercise group too :-

[img]http://ajpregu.physiology.org/content/303/6/R571/F3.medium.gif [/url] " nonexercise activity was numerically increased by 37% in MOD compared with CON (8.8 × 103 counts/day, CI: −1.0, 18.7, P = 0.09) "[/img]

emnk5308

I just do HIIT.


But when I did longer sessions, it was for the purpose of creating a caloric deficit not "fat burning".

What is this? I've heard of it before but don't understand.. :embarassed:

It is High Intense Interval Training
You put your body through short bursts of intense physical exertion...with small resting periods in between. It helps to confuse the muscles, and revs up the metabolism & heart rate very quickly!

Ahh, Duh =p Like doing Crossfit?

myofibril

Do I really need to spell this out....

Yeah, give us your explanation of the lack of difference in weight loss. Is it a Taubes like "exercise makes you hungry" so the high exercise group ate more ? The authors were leaning that way "there is some indication that EI increased in HIGH, driving the small but quantifiable degree of compensation"

Yes, to some degree. Exercise is known to stimulate hunger in some people (though weirdly it has the opposite effect in others.) Therefore, if an individual compensates for the deficit they have created through exercise by increasing ad libitum intake then we know that there will be little difference in weight loss.

In addition, allowing participants to self report intake outside of a metabolic ward conditions is notoriously prone to error (there was only particular study I recall where obese participants where specifically chosen because they were diet resistance and swore they could not loss weight on a self reported intake of 1,200 calories. It transpires they were under estimating their intake by 50%....) The diet tracking side of exercise studies is normally where they fall down and why drawing any solid conclusions from them is difficult.

I would say that studies like this miss a blindingly obvious point which I would like to see research on. That is if you do more exercise, specifically aerobic, this creates a deficit but also the ability to eat more food and still remain under TDEE. If the individual ate more due to the exercise they had performed but still remained under TDEE what would the difference in body composition be in comparison to someone who simply ate less to create the same deficit.

Are all deficits created equal?

Personally, I think the answer is no from the limited research I have seen. Logically, if you eat more and relatively well then you provide your body with more essential nutrients and "building blocks" like amino acids etc to work with which would shunt calories towards LBM / muscle building and away from fat storage - the eat more do more approach.

yarwell

In addition, allowing participants to self report intake outside of a metabolic ward conditions is notoriously prone to error

indeed, though often I suspect people reach for the "under-reporting" excuse/reason when they can't explain their findings any other way.

In this study they did not intend to control energy intake or maintain a certain deficit - " they were told not to impose any dietary restrictions during study participation but to select food items without restraint. " - as it was in effect a test of an exercise regime alone. If food intake varied that's at least in part a consequence of the thing they were testing - what are the consequences of telling humans to double their exercise. The monitoring of exercise was more rigorous than food.

Energy deficit was just back calculated from fat and lean body mass losses, rather than by energy balance.

needamulligan

bump