The article mentions that a substance (lactose-phenylalanine) appears
after exercise in several animal studies. There's a suggestion of a
strong connection of this to reduced appetite. But this isn't
explained and more importantly there's no hypothesised mechanism. Why
would it be a metabolic advantage to reduce hunger after exertion?
Maybe it creates a buffer-period. Otherwise, common sense/intuition
would say we feel hungrier after exercise. What gives?
“After” is what happens now, when we are in control of our time “I will hit the gym for one hour”. In our past, physical activity was a survival-related task with no fixed end time (chasing a prey, fleeing from danger). I think for our ancestors it would happen during exertion. It would not be advantageous to feel increasingly hungry while exercising, the same way that it makes sense for adrenaline to block pain during a fight. Less distraction, more survival
I think it helps if you think of exercise as what it is: lying.
A longshoreman is strong because he spends all day shifting cargo around. Steve is big and buff because he tricks his body into thinking shifting cargo around all day is a likely scenario.
Muscle is expensive. The body is very stingy with keeping muscle you don't need on a regular basis. A gym visit is trying to simulate the behavior of all-day exertion without having to abandon all of the other activities you want to fill your day with.
>>> Otherwise, common sense/intuition would say we feel hungrier after exercise. What gives?
I would hypothesize that recovery and digestion are two metabolically intensive activities that the body is unable to do them simultaneously, so it would make sense to suppress hunger while the body recovers itself from exercise.
Now, the supplement industry has made us believe that if you don't consume food within the magical anabolic window, you recovery will be impaired. Nonsense if you ask me.
Yeah that's exactly right. Even when I over-strain myself my body is still kind of in a shock for 40-50 minutes (during which I also drink a lot of water) and then suddenly boom, I can eat an elephant.
Same with digestion. I found out the hard way that taking a walk after the restaurant is an awful idea. The body really needs a relaxed pose and to be not doing anything else for at least an hour after a meal (with slowed down metabolisms this can go up to 3h, sadly) so you can properly get your nutrients. Only then you should be doing another activity.
Genetic selection has a lot of trouble differentiating between correlation and causation. That is one of the ways in which intellect has allowed us to evolve so fast that our genes are sometimes becoming a problem.
Hibernation and torpor cycles are alternating between metabolic modes that are tied to the seasons, seasons are tied to weather, and exercise levels are tied to the weather directly, and to seasons indirectly - I'm gathering roots today because the sun is out, but I'm not walking to the next village because we usually have snow storms this time of year, so I could get halfway there and then die in a blizzard.
