The body loses water and salts in sweat. explain why drinking large volumes of plain water after exercising may affect the salt balance in the body.

Because it rehydrates the body from the fluids lost through sweat and prevents dehydration

The person who utilize the progression principle will keep adding the difficulty of the exercise that he's doing, while the person who does not, will only stay stagnant.  the person that utilize progression principle, will get a stronger endurance because now his body is conditioned to do harsher routines.{the answer was already on verified)