Exercise, The Exercise Paradox and You!

A place to get your questions answered from McDougall staff dietitian, Jeff Novick, MS, RDN.

Moderators: JeffN, carolve, Heather McDougall

Exercise, The Exercise Paradox and You!

Postby JeffN » Tue Feb 06, 2018 12:26 pm

(I am putting this thread together to organize the posts on this topic. The first four posts are from 2017 and appeared elsewhere in this forum and the Lounge)

For those who follow my forum, here are a few links to some research that has been going on over the last few years (and decades) on activity/exercise called The Exercise Paradox. It has to do with how much exercise is enough and are much higher levels of exercise/activity the reason why ancestral and hunter-gatherers had an easier time avoiding excess weight and obesity. It also looks at the role our modern sedentary lifestyle plays in the weight equation reinforcing several points in this thread. I am working on a graphic representation of what all this is saying.

My original thread on exercise:

Exercise, Health & You: How Much Is Enough?
viewtopic.php?f=22&t=43482

In Health
Jeff


SCIENTIFIC AMERICAN
FEBRUARY 2017
The Exercise Paradox
https://www.scientificamerican.com/arti ... e-paradox/

Studies of how the human engine burns calories help to explain why physical activity does little to control weight—and how our species acquired some of its most distinctive traits

(Unfortunately, this one is behind a pay wall. Here is a link to a recording of it and a PDF of it that is available for a short time)

https://us.ivoox.com/en/the-exercise-pa ... 909_1.html

http://dropcanvas.com/1fcrc



Why do individuals not lose more weight from an exercise intervention at a defined dose? An energy balance analysis.
Obes Rev. 2012 Oct;13(10):835-47.
doi: 10.1111/j.1467-789X.2012.01012.x. Epub 2012 Jun 11.
https://www.ncbi.nlm.nih.gov/pubmed/22681398

Abstract
Weight loss resulting from an exercise intervention tends to be lower than predicted. Modest weight loss can arise from an increase in energy intake, physiological reductions in resting energy expenditure, an increase in lean tissue or a decrease in non-exercise activity. Lower than expected, weight loss could also arise from weak and invalidated assumptions within predictive models. To investigate these causes, we systematically reviewed studies that monitored compliance to exercise prescriptions and measured exercise-induced change in body composition. Changed body energy stores were calculated to determine the deficit between total daily energy intake and energy expenditures. This information combined with available measurements was used to critically evaluate explanations for low exercise-induced weight loss. We conclude that the small magnitude of weight loss observed from the majority of evaluated exercise interventions is primarily due to low doses of prescribed exercise energy expenditures compounded by a concomitant increase in caloric intake.


Hunter-Gatherer Energetics and Human Obesity
Published: July 25, 2012
PLoS ONE 7(7): e40503.
http://dx.doi.org/10.1371/journal.pone.0040503
http://journals.plos.org/plosone/articl ... ne.0040503

Abstract

Western lifestyles differ markedly from those of our hunter-gatherer ancestors, and these differences in diet and activity level are often implicated in the global obesity pandemic. However, few physiological data for hunter-gatherer populations are available to test these models of obesity. In this study, we used the doubly-labeled water method to measure total daily energy expenditure (kCal/day) in Hadza hunter-gatherers to test whether foragers expend more energy each day than their Western counterparts. As expected, physical activity level, PAL, was greater among Hadza foragers than among Westerners. Nonetheless, average daily energy expenditure of traditional Hadza foragers was no different than that of Westerners after controlling for body size. The metabolic cost of walking (kcal kg−1 m−1) and resting (kcal kg−1 s−1) were also similar among Hadza and Western groups. The similarity in metabolic rates across a broad range of cultures challenges current models of obesity suggesting that Western lifestyles lead to decreased energy expenditure. We hypothesize that human daily energy expenditure may be an evolved physiological trait largely independent of cultural differences


Relation between Caloric Intake, Body Weight, and Physical Work
STUDIES IN AN INDUSTRIAL MALE POPULATION IN WEST BENGAL
Am J Clin Nutr
March 1956
vol. 4 no. 2 169-175

http://ajcn.nutrition.org/content/4/2/169.abstract

The relation between caloric intake, body weight, and physical work was established in a group of 213 mill workers in West Bengal. These workers covered a wide range of physical activity, from sedentary to very hard work. It was found that caloric intake increases with activity only within a certain zone ("normal activity"). Below that range ("sedentary zone") a decrease in activity is not followed by a decrease in food intake but, on the contrary, by an increase. Body weight is also increased in that zone. The picture is similar to that previously found in experimental animals.



Popular Press Articles

Why Physical Activity Does Little to Control Weight
SkepDoc's Corner
February 16, 2017
http://www.csicop.org/specialarticles/s ... rol_weight


Debunking the Hunter-Gatherer Workout
NY TImes
August 24, 2012
https://mobile.nytimes.com/2012/08/26/o ... rkout.html


Dieting vs. Exercise for Weight Loss
NY Times
August 1, 2012
https://mobile.nytimes.com/blogs/well/2 ... /?referer=
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Tue Feb 06, 2018 12:28 pm

Two recent discussions in the forum on the Exercise Paradox I was involved in

The Exercise Paradox
viewtopic.php?f=1&t=55287

Exercise Paradox
viewtopic.php?f=22&t=55296

In Health
Jeff
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Tue Feb 06, 2018 12:29 pm

From another discussion in this forum...

The Exercise Paradox is not carved in stone but a hypothesis that may explain more about what has been observed over quite some time. That is how I look at it and that there is much more to know.

There has always been a few issues with the energy equation and over the decades we have learned more and more that have helped us put it into better perspective. Some of this has had to do with the metabolism of calories in (which we understand much better now) and some of it has had to do with the metabolism of energy out (which we are also understanding more about all the time). As far as I can remember, there has always been the comment that you win the battle over weight loss with the plate, not the treadmill.

So far I would say...

- Being sedentary is very unhealthy.

- Our bodies are meant to move and be active and there are quite a few health benefits we derive from that, but it doesn't take much activity/movement to get us from being sedentary to this level where we incur these health benefits with little risk.

- A higher level than this amount may not offer any more benefits or calorie burn and any added benefit or energy expenditure will be limited but may also increase certain risks.

- Excessive/extreme forms of aerobic exercise may not be burning as many calories as once thought as it appears the body may be undergoing a metabolic adaption to conserve/constrain energy expenditure

I hope that helps

In Health
Jeff
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Tue Feb 06, 2018 12:29 pm

Also from another discussion in this forum in regard to the value of exercise

I never primarily exercised to lose weight but like most people I thought it helped. The main reason I exercise is because it is the most effective thing I have tried for battling depression. And also resistance exercise to maintain muscle and strength and bone strength.


These are all good reasons to exercise and be active and do not require excessive amounts to reap the benefits

In Health
Jeff
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Tue Feb 06, 2018 12:32 pm

JeffN wrote:So far I would say...

- Being sedentary is very unhealthy.

- Our bodies are meant to move and be active and there are quite a few health benefits we derive from that, but it doesn't take much activity/movement to get us from being sedentary to this level where we incur these health benefits with little risk.

- A higher level than this amount may not offer any more benefits or calorie burn and any added benefit or energy expenditure will be limited but may also increase certain risks.

- Excessive/extreme forms of aerobic exercise may not be burning as many calories as once thought as it appears the body may be undergoing a metabolic adaption to conserve/constrain energy expenditure.

I hope that helps

In Health
Jeff


About a year ago, I made the above 4 points into a graph and slide for both discussion with my colleagues and also to present occasionally at the program. The most common question I would get is, what is that amount of exercise (and energy expenditure) that is needed to move us from point 1 to point 2. My answer was around 300-350 as a bare minimum and about 550-600 at the higher end. My reasoning behind this range is based on the amount of calories need to be active 30-60 minutes per day (i.e., brisk walk), and not be sedentary the rest of the day for an average adult. To see why I used this amount, you can read my full first post in my main exercise thread.

One of the lead researches behind the Exercise Paradox, Dr. Herman Ponzer, gave a recent talk, which you can see in this video (thanks KostasP) and he estimates it at about 600 cal/day.

https://www.youtube.com/watch?v=YyLcaPcvDJg

Just another confirmation that:

- The battle of weight is won at the plate.
- Avoid being sedentary.
- Being active, whether through formal exercise (or the equivalent activity) is important.
- You can maximize the health benefit of this without risking injury with ~30-60 min/day of mod exercise or the equivalent activity.
- Brisk Walking may be one of the easiest, safest, inexpensive and accessible forms of moderate aerobic activity***.

In Health
Jeff

*** Brisk walking is one of the best forms of moderate aerobic activity but we also want to include some focus on balance, flexibility and strength, all of which do not take a lot of time and can easily fit into the 30-60 minutes per day.

PS here is the graph I made representing the original 4 points, which was inspired by the graphic genius of Dr Lisle.

Image
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Thu Apr 12, 2018 5:47 am

Exercise Paradox shown in mice.


Reduced Nonexercise Activity Attenuates Negative Energy Balance in Mice Engaged in Voluntary Exercise
Diabetes 2018 Mar; db171293. https://doi.org/10.2337/db17-1293
http://diabetes.diabetesjournals.org/co ... /db17-1293

Abstract

Exercise alone is often ineffective for treating obesity despite the associated increase in metabolic requirements. Decreased nonexercise physical activity has been implicated in this resistance to weight loss, but the mechanisms responsible are unclear. We quantified the metabolic cost of nonexercise activity, or “off-wheel” activity (OWA), and voluntary wheel running (VWR) and examined whether changes in OWA during VWR altered energy balance in chow-fed C57BL/6J mice (n = 12). Energy expenditure (EE), energy intake, and behavior (VWR and OWA) were continuously monitored for 4 days with locked running wheels followed by 9 days with unlocked running wheels. Unlocking the running wheels increased EE as a function of VWR distance. The metabolic cost of exercise (MCE; kcal/m traveled) decreased with increasing VWR speed. Unlocking the wheel led to a negative energy balance, but also decreased OWA, which was predicted to mitigate the expected change in energy balance by ∼45%. A novel behavioral circuit involved repeated bouts of VWR, and roaming was discovered and represented novel predictors of VWR behavior. The integrated analysis described here reveals that the weight loss effects of voluntary exercise can be countered by a reduction in nonexercise activity.


NY Times article
Why Exercise Alone May Not Be the Key to Weight Loss
Phys Ed
By GRETCHEN REYNOLDS APRIL 11, 2018

https://nyti.ms/2GRxU46
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Sun Dec 23, 2018 8:23 am

Hunter‐gatherers as models in public health
Obesity Reviews Volume 19, Issue S1
H. Pontzer B. M. Wood D. A. Raichlen
First published: 03 December 2018
https://doi.org/10.1111/obr.12785

Full Text
https://onlinelibrary.wiley.com/doi/ful ... /obr.12785

Summary
Hunter‐gatherer populations are remarkable for their excellent metabolic and cardiovascular health and thus are often used as models in public health, in an effort to understand the root, evolutionary causes of non‐communicable diseases. Here, we review recent work on health, activity, energetics and diet among hunter‐gatherers and other small‐scale societies (e.g. subsistence farmers, horticulturalists and pastoralists), as well as recent fossil and archaeological discoveries, to provide a more comprehensive perspective on lifestyle and health in these populations. We supplement these analyses with new data from the Hadza, a hunter‐gatherer population in northern Tanzania. Longevity among small‐scale populations approaches that of industrialized populations, and metabolic and cardiovascular disease are rare. Obesity prevalence is very low (<5%), and mean body fat percentage is modest (women: 24–28%, men: 9–18%). Activity levels are high, exceeding 100 min d−1 of moderate and vigorous physical activity, but daily energy expenditures are similar to industrialized populations. Diets in hunter‐gatherer and other small‐scale societies tend to be less energy dense and richer in fibre and micronutrients than modern diets but are not invariably low carbohydrate as sometimes argued. A more integrative understanding of hunter‐gatherer health and lifestyle, including elements beyond diet and activity, will improve public health efforts in industrialized populations.


From the article

The surprising discovery that high levels of physical activity do not invariably result in elevated TEE and PAL 6, 7, 25-27 (Fig. 2) forces us to rethink the mechanisms by which exercise promotes health. The hypothesis that industrialized populations are prone to metabolic disease because they are less active and therefore expend fewer calories per day is not supported by metabolic measurements from hunter‐gatherers and other small‐scale societies 6, 7, 25, 26 (Fig. 2).

In Health
Jeff
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Wed Apr 17, 2019 6:54 pm

Studying Preindustrial Societies Informs us About How to Be Healthy. Podcast with Herman Pontzer
HumanOS Radio

https://soundcloud.com/humanosradio/stu ... an-pontzer

For the vast majority of human history, our species lived hunter-gatherer lifestyles. We can therefore learn much about how humans probably once lived by studying preindustrial societies.

Research on preindustrial societies has consistently shown that these people have exemplary metabolic health. And when we consider that modern humans are succumbing to chronic diseases at an alarming rate, we clearly have much to learn from preindustrial people.

In this episode of humanOS Radio, Greg Potter speaks with Professor Herman Pontzer about what Herman has learned from his research on hunter-gatherers. Herman's findings led him to develop the counterintuitive hypothesis that how physically active we are each day may scarcely affect how many calories we burn…

… no, I’m not kidding.

As he explains in the podcast, however, this hypothesis in no way discounts the importance of being physically active – far from it!

Tune in for more on Herman’s fascinating research on physical activity, diet, and more.
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Tue Jun 18, 2019 6:08 am

Study

Extreme events reveal an alimentary limit on sustained maximal human energy expenditure
Science Advances 05 Jun 2019: Vol. 5, no. 6, eaaw0341
DOI: 10.1126/sciadv.aaw0341

https://advances.sciencemag.org/content ... -ios-share

Abstract
The limits on maximum sustained energy expenditure are unclear but are of interest because they constrain reproduction, thermoregulation, and physical activity. Here, we show that sustained expenditure in humans, measured as maximum sustained metabolic scope (SusMS), is a function of event duration. We compiled measurements of total energy expenditure (TEE) and basal metabolic rate (BMR) from human endurance events and added new data from adults running ~250 km/week for 20 weeks in a transcontinental race. For events lasting 0.5 to 250+ days, SusMS decreases curvilinearly with event duration, plateauing below 3× BMR. This relationship differs from that of shorter events (e.g., marathons). Incorporating data from overfeeding studies, we find evidence for an alimentary energy supply limit in humans of ~2.5× BMR; greater expenditure requires drawing down the body’s energy stores. Transcontinental race data suggest that humans can partially reduce TEE during long events to extend endurance.




Article

Pushing the Limits of Human Endurance
When we work out rigorously on a regular basis, our bodies adjust to limit our ability to expend energy, a new study shows.
NY Times
By Gretchen Reynolds
June 12, 2019

Our bodies seem to adjust to prolonged, repeated physical exertion and its energy demands by burning fewer — instead of more — calories over the course of the day, even if our exertions continue at the same level, according to a surprising new study of energy expenditure conducted during a 20-week running race across the United States.

https://www.nytimes.com/2019/06/12/well ... rance.html
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Fri Oct 29, 2021 6:19 am

We now have a formal estimate of the conservation/compensation

Energy compensation and adiposity in humans, Current Biology, Volume 31, Issue 20, 2021, Pages 4659-4666.e2, ISSN 0960-9822,
https://doi.org/10.1016/j.cub.2021.08.016.

(https://www.sciencedirect.com/science/a ... 2221011209)

Highlights

•Energy compensation in humans was analyzed from daily and basal energy expenditure

•Reduced BEE results in energy compensation of 28%

•Degree of energy compensation varied between people of different body composition


Summary

Understanding the impacts of activity on energy balance is crucial. Increasing levels of activity may bring diminishing returns in energy expenditure because of compensatory responses in non-activity energy expenditures.1, 2, 3 This suggestion has profound implications for both the evolution of metabolism and human health. It implies that a long-term increase in activity does not directly translate into an increase in total energy expenditure (TEE) because other components of TEE may decrease in response—energy compensation. We used the largest dataset compiled on adult TEE and basal energy expenditure (BEE) (n = 1,754) of people living normal lives to find that energy compensation by a typical human averages 28% due to reduced BEE; this suggests that only 72% of the extra calories we burn from additional activity translates into extra calories burned that day. Moreover, the degree of energy compensation varied considerably between people of different body compositions. This association between compensation and adiposity could be due to among-individual differences in compensation: people who compensate more may be more likely to accumulate body fat. Alternatively, the process might occur within individuals: as we get fatter, our body might compensate more strongly for the calories burned during activity, making losing fat progressively more difficult. Determining the causality of the relationship between energy compensation and adiposity will be key to improving public health strategies regarding obesity.
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am

Re: Exercise, The Exercise Paradox and You!

Postby lucidguppy » Sat Nov 06, 2021 11:30 am

I find this subject fascinating - thanks for collecting all this information. All the math is daunting though.

Funny how Jeff's caloric density charts in https://youtu.be/0CdwWliv7Hg?t=2546 lines up with that chart in the Herman Ponzer video from seen at https://youtu.be/YyLcaPcvDJg?t=462

Of course Jeff you know all this already - but its fun figuring it out myself (I'm probably wrong but here goes...)

We eat 4 lbs of food per day (upper end of range)

4 lbs / day * 550 cal/lb = 2200 cal / day... and in that chart in the Herman Ponzer expenditure graph - kcal went from 3.2 to 3.6 kcal per day expenditure.

No wonder 550 cal/lb is the magic number for losing weight.

In your talk 400 cal/lb was always lose =1600cal/day
Above 800 cal/lb was weight gain - that's 3200 cal/day - so the lowest activity group probably lines up with 3200 cal/day - and why 800 cal/lb is the lower limit for weight gain.
User avatar
lucidguppy
 
Posts: 188
Joined: Sat Oct 17, 2015 6:42 am
Location: Massachusetts

Re: Exercise, The Exercise Paradox and You!

Postby JeffN » Sat Nov 06, 2021 1:58 pm

Wow. Thanks!

Just to clarify...

The average range is around 3-5 (but there are some interesting outliers)

The "pretty much" always lose wt was under 300/400.

My chart above (the imitation of Dr Lisle graphics), lines up with it all too.

That was my guess in one of the threads, that I think there is a 400-600 calorie buffer. And he said 600.

Interesting!!

Thanks again!
Jeff
User avatar
JeffN
 
Posts: 9412
Joined: Tue Jan 08, 2008 5:56 am


Return to Jeff Novick, RD

Who is online

Users browsing this forum: No registered users and 15 guests



Welcome!

Sign up to receive our regular articles, recipes, and news about upcoming events.