Homeostasis is something I'm familiar with but the idea of generating heat without calories is a new one to me?
A "calorie" is actually a unit of heat energy.
From Wiki:
"Shivering is a bodily function in response to early hypothermia in warm-blooded animals. When the core body temperature drops, the shivering reflex is triggered. Muscle groups around the vital organs begin to shake in small movements in an attempt to create warmth by expending energy. Shivering can also be a response to a fever as a person may feel cold, though their core temperature is already elevated.
Located in the dorsomedial portion of the hypothalamus near the wall of the third ventricle is an area called the primary motor center for shivering. This area is normally inhibited by signals from the heat center in the anterior hypothalamic-preoptic area but is excited by cold signals from the skin and spinal cord. Therefore, this center becomes activated when the body temperature falls even a fraction of a degree below a critical temperature level.
Increased muscular activity results in wasted heat - here the heat is utilized for warmth."
Now Wiki is by no means authorative but that is indeed the usual definition of shivering, deliberate burning of energy, ie calories, to produce heat.
But you say the body, having deliberately burnt some energy for heat, compensates by not burning energy elsewhere?
Rather than digging into that issue specifically, I think the important word here is not homeostasis, which is just the body seeking balance, but the other word - "stress".
If the body is stressed to the point where it will deliberately burn energy just for heat, then compensate for that by denying parts of itself their normal energy levels, however you look at it, you have a body with an energy shortage.
Most forms of exercise can actually dampen your appetite for awhile. Indeed a heavy session in the gym can leave you feeling like throwing up let alone facing a large meal - but the munchies you get after slimming are not like that. Be it due to a different mechanism, perhaps considered more of an emergency, whatever, fact is a lot of peeps are peckish after a swim but not after a gym.
Yes you should have a post workout meal anyway but the studies I've seen show peeps eat considerably more after swimming than after other forms of exercise.
Most forms of exercise you're trying to cool down after, with swimming you come out with the shivers and are trying to warm up. To me it makes sense and studies do seem to confirm it - you end up eating more calories than you burnt from the exercise of swimming.
Yes your body may compensate - but then you compensate by eating more than you normally would.
B.
