There is a fair amount of literature reporting that in humans, basal metabolic rate (BMR) decreases in response to negative energy balance (and thus weight loss). This negative energy balance is often generated by an exercise intervention, increasing activity energy expenditure. I am interested to know whether BMR decreases in response to (long-term) increases in activity *per se*. In other words, are there any studies demonstrating that a long-term increase in exercise/activity and thus activity energy expenditure, without a substantive decrease in body weight, is associated with a decrease in BMR. (There are some predictions that this will be the case, based on the idea that the body is seeking to compensate for the increase in energy expenditure in activity with a decrease in energy expenditure for basal physiological processes. But is there evidence for it?)
Dear Dr Lewis Halsey ,
No, the BMR is actually not decrease much when one is ageing. However, when there are stresses (like exercise, starvation, pathogen invasion, etc.), autophagy will be upregulated. This upregulation of autophagy serves as recycling process to reuse the waste cellular components and pathogens, and they become an extra source of nutrients and energy:
Article Autophagy and the Integrated Stress Response
In these cases, restrictive eating is necessary to avoid weight gain.
Good day Dr. Halsey,
In a fair average intensity and duration exercise ( so excluding top performance extremes) I woud say no ! Two reasons : 1) Muscle mass shoud fairly grow with regurlar exercise stimularion and last time when I looked arround, more muscles means higher metabolism at rest metabolism. 2) There must be a fair amount of energy the body strives to spare and preserve for basal physiological processes. Intens ( and acute) exercise might disturb it to a certain extend, but evolutive survival compensatory mechanisms might take over and reset the energy balance on longterm. It only make sens, following an entropic energy optimisation pattern.
Best, DCM
I suppose it also match Dr. Liu answer here-up, the autophagy modulation beeing such an energetic evolutive survival & compensatory mechanism in mammals.
A thought that was provoked by the idea of using metformin to loose fat.
Metformin converts macrophage to m2 anti inflammatory state which helps limit adipose tissue. Moderate exercise mimic this effect.
If you engage is excessive exercise, where tissue is damaged, you will release damps that trigger inflammation and m1 macrophage that would promote adipocyte activity. Chronically. This is all theoretical, just an idea
- Badges
- Science topic
- Similar topics
- Biological Science
- Zoology
- Ornithology