How to Measure Your Sweat Rate Based on Your Weight Before and After Exercise

Weigh yourself before, weigh yourself afterwards. You've lost 300 grams. Therefore, you must make sure every time you run for an hour, you take in 300 militers of fluid. There are so many problems with that, because not all those 800 grams are fluid. So the key thing there is, your body doesn't regulate weight loss. That's not what drives the physiology of thirst. What does drive those is the osmelality. And it is one of the most sensitive systems we have. This is an argument for thirst. Our plasma osmelability is regulated at a level between two 80 and 300. The thirst mechanism is so sensitive that when that changes by three