p90x when to workout

Muscle Size During and After Working Out?

During my P90X Workouts when i build up a sweat and im working hard at the activity my Biceps are just bulging i mean at least 2 times the normal size, and hardness after i cool down and im done working out it goes back to the normal size, why does this happen?

they are flexxed or stressed when ur working out… after working out they are relaxxed.