Exercise Paradox

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Exercise Paradox

Postby Skip » Sat Apr 22, 2017 2:48 pm

Since the "Exercise, Health & You: How Much Is Enough?" thread is locked and I wanted to comment on it, I started a new topic. I hope this OK with you. In the original post of this thread, you wrote the following (in red):

We can also look at the issue another way, which I have discussed many times before. Let us say we have two identical people.

- one maintains a BMI of 18.5 and does so through a very healthy diet. They exercise moderately about 30 minutes a day, 5x a week and burn a total of about 2000 calories per day. To maintain their BMI, they consume about 2000 calories per day.

- the other identical person also maintains a BMI of 18.5 and does so through a very healthy diet. However, they exercise vigorously about 1.5 - 2 hours a day (or more) and burn a total of about 3000-3500 calories per day. To maintain their BMI, they consume about 3000-3500 calories per day.

All the studies in animals and the recent ones in humans show the first one will do much better and live longer and healthier.

Remember, a little is good, a little more may be a little better, but not that much and lots more is not good.


The latest post on this thread, dated April 8, 2017 discusses an article called the Exercise Paradox. This article presents the following concept: viewtopic.php?f=1&t=55287#p560778

If the Constrained model of energy expenditure is accurate, then both identical people in your example would be burning approximately the same amount of calories per day regardless of their differing exercise regimes.

Now that this study has come out, does it change your thoughts on this scenario? It seems to be based on the Additive model.
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Re: Exercise Paradox

Postby JeffN » Sat Apr 22, 2017 3:04 pm

Skip wrote:Now that this study has come out, does it change your thoughts on this scenario? It seems to be based on the Additive model.


No. Not at all

Calories are only one issue

Another important issue in the scenario I described is the extra wear and tear on the body from the extra exercise along with all the other concerns of "over" exercise expressed in that same thread. There have also been CR studies showing that exercise (in excess) negates some of the benefits of the CR.

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Re: Exercise Paradox

Postby Skip » Sat Apr 22, 2017 4:07 pm

JeffN wrote:
Skip wrote:Now that this study has come out, does it change your thoughts on this scenario? It seems to be based on the Additive model.


No. Not at all

Calories are only one issue

Another important issue in the scenario I described is the extra wear and tear on the body from the extra exercise along with all the other concerns of "over" exercise expressed in that same thread. There have also been CR studies showing that exercise (in excess) negates some of the benefits of the CR.

In Health
Jeff


But what about the assumption that two identical people would be expending large differences in energy expenditure? If the constraint model is correct, this couldn't happen. The guy eating more calories wouldn't be able to maintain an 18.5 BMI (or the other guy would starve).

I agree with everything else you say about over exercise. Maybe I'm being to nit-picky here........if so, I"m sorry :D
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Re: Exercise Paradox

Postby JeffN » Sat Apr 22, 2017 4:23 pm

Skip wrote:
JeffN wrote:
Skip wrote:Now that this study has come out, does it change your thoughts on this scenario? It seems to be based on the Additive model.


No. Not at all

Calories are only one issue

Another important issue in the scenario I described is the extra wear and tear on the body from the extra exercise along with all the other concerns of "over" exercise expressed in that same thread. There have also been CR studies showing that exercise (in excess) negates some of the benefits of the CR.

In Health
Jeff


But what about the assumption that two identical people would be expending large differences in energy expenditure? If the constraint model is correct, this couldn't happen. The guy eating more calories wouldn't be able to maintain an 18.5 BMI (or the other guy would starve).

That's

I agree with everything else you say about over exercise. Maybe I'm being to nit-picky here........if so, I"m sorry :D


As I said, calories are one issue but not that only issue in the above scenario I posted.

So, if the Exercise Paradox is 100% true (which it may be and if it is not 100% it may be 80% or so***), my conclusion remains the same as the one doing higher exercise would have to adjust his caloric intake appropriately to maintain the BMI of 18.5 or they would gain weight.

That would leave the two scenario's with the same caloric intake, the same BMI (or one with higher BMI), however, the one would still have a much higher levels of exercise and all the accompanying issues of that.

Hence, the conclusion remains.

I am working on graphic to try and help explain what this all may mean in various scenarios.

I dont see how it really changes anything other that just another good reason not to overdo the exercise. Besides the potential harm from the excess exercise, you may not be getting all the benefit of burning the calories you thought you were.

***There appears to be other data that says while this paradox does exist, it is not 100% and there may still be some extra calorie burn.

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Re: Exercise Paradox

Postby Skip » Sat Apr 22, 2017 8:43 pm

JeffN wrote:***There appears to be other data that says while this paradox does exist, it is not 100% and there may still be some extra calorie burn.


There must be. Suppose one's constraint limit is 2,500 calories/day and that person runs a marathon and burns 2,600 calories in it so that marathon alone exceeds the constraint limit for the day. Perhaps that difference will be made up in the next day or next week or some designated time frame.
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Re: Exercise Paradox

Postby JeffN » Sat Apr 22, 2017 8:53 pm

Skip wrote:
JeffN wrote:***There appears to be other data that says while this paradox does exist, it is not 100% and there may still be some extra calorie burn.


There must be. Suppose one's constraint limit is 2,500 calories/day and that person runs a marathon and burns 2,600 calories in it so that marathon alone exceeds the constraint limit for the day. Perhaps that difference will be made up in the next day or next week or some designated time frame.


Turns out that we will consciously (or subconsciously) down regulate our activity after a period of higher intensity whether it is a marathon or a session of HIIT, usually in the area of NEAT &/or other physical activity/exercise, or we burn out and experience exhaustion.

There also "appears" to be some metabolic compensation (in regard to down regulation of RMR) which is not fully understood yet.

Sadly, the reverse is not true in regard to a sedentary lifestyle.

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Re: Exercise Paradox

Postby JeffN » Wed Apr 26, 2017 7:45 am

JeffN wrote:Turns out that we will consciously (or subconsciously) down regulate our activity after a period of higher intensity whether it is a marathon or a session of HIIT, usually in the area of NEAT &/or other physical activity/exercise, or we burn out and experience exhaustion.


Or other damage

Intense training without proper recovery may compromise bone health in elite rowers
Date: April 25, 2017
Source: Federation of American Societies for Experimental Biology (FASEB)
(This was presented and is currently unpublished but we have published data saying the same****)

Summary:
Bone mineral density, an indicator of bone strength, typically increases with regular exercise, acting as a protective mechanism against bone fractures and osteoporosis. But a new study suggests that the extended, high-intensity training sessions of elite athletes could reverse beneficial bone changes.

https://www.sciencedaily.com/releases/2 ... 153814.htm

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****Overreaching/Overtraining: More Is Not Always Better
Roy, Brad A. Ph.D., FACSM, FACHE
ACSM'S Health & Fitness Journal: March/April 2015 - Volume 19 - Issue 2 - p 4–5
doi: 10.1249/FIT.0000000000000100

Johnson, MB; Thiese, SM (1992). "A review of overtraining syndrome-recognizing the signs and symptoms." (PDF). Journal of athletic training. 27 (4): 352–4. PMC 1317287Freely accessible. PMID 16558192. Retrieved 25 June 2014.

MacKinnon, Laurel (30 May 2000). "Overtraining effects on immunity and performance in athletes". Immunology and Cell Biology. 78: 502–509. doi:10.1111/j.1440-1711.2000.t01-7-.x.

Budgett, Richard (10 March 1998). "Fatigue and underperformance in athletes: the overtraining syndrome" (PDF). British Journal of Sports Medicine. 32: 107–110. doi:10.1136/bjsm.32.2.107.

Steinacker, Lehmann, Lormes, Opitz-Gress, Jürgen (17 March 1997). "Training and overtraining: an overview and experimental results in endurance sports.". Sports Medicine and Physical Fitness.
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Re: Exercise Paradox

Postby JeffN » Tue Sep 04, 2018 6:08 am

JeffN wrote:Turns out that we will consciously (or subconsciously) down regulate our activity after a period of higher intensity whether it is a marathon or a session of HIIT, usually in the area of NEAT &/or other physical activity/exercise, or we burn out and experience exhaustion.


Even with moderate exercise, there is energy conservation/compensation during the rest of the day.

In Health
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Use of Time and Energy on Exercise, Prolonged TV Viewing, and Work Days
Am J Prev Med. 2018 Sep;55(3):e61-e69. doi: 10.1016/j.amepre.2018.04.036. Epub 2018 Jul 19.

Introduction
The goal of this study was to describe differences in time use and energy expenditure associated with exercise, prolonged TV viewing, and work days in a longitudinal study of older adults.

Methods
Participants were 1,020 adults who completed previous-day recalls that provided a profile of the use of time in sedentary and physical activity. Time use and physical activity energy expenditure were predicted for each type of day (exercise, prolonged TV, work) using linear mixed models, adjusting for age, sex, season of the year, and day of the week. Data were collected in 2012–2013; analysis was completed in 2017.

Results
Exercise days had less sedentary time (–0.37 hours/day) and light activity (–0.29 hours/day), and less household, work, and shopping activities, such that the increase in total physical activity energy expenditure on exercise days (2.83 MET-hours/day) was only about half that expended during exercise (5.98 MET-hours/day). Prolonged TV viewing days had more total sedentary time (0.86 hours/days) and less light (–0.45 hours/day) and moderate–vigorous intensity activity (–0.41 hours/day), and thus lower total physical activity energy expenditure (–2.43 MET-hours/day). Work days had less sleep (–0.91 hours/day) and more total sedentary time (1.32 hours/day).

Conclusions
Exercise days had more physical activity energy expenditure, but because of reductions in other activities, only about half of the energy expended during exercise was added to total daily physical activity energy expenditure. Prolonged TV viewing days had less physical activity energy expenditure and less moderate–vigorous activity. These findings provide new insights into possible compensation associated with exercise, and suggest a strong link between TV viewing and physical inactivity.
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