A hard cardio workout to the degree I spend 15-20 minutes with the only possible thought being "can I stop now?!?!". To reach that takes 20 minutes, and then I'

A hard cardio workout to the degree I spend 15-20 minutes with the only possible thought being "can I stop now?!?!". To reach that takes 20 minutes, and then I'm spent, soaking and start to cleanup. In total such a workout is an hour, and afterwards my mind is clear. When I workout during mid-project, it aids my mental clarity. When I workout during a deadline, it clears my head for solutions needed then or to prepare for the next.