Cardiac exercises! They get your heart pumping blood quicker to strengthen it! :)
A short term goal would be to abstain from sex or masturbation for a health reason: waiting for a UTI, STD or other issue (from a procedure, perhaps) until healing comes.A long term goal would be waiting for marriage to have sex and then committing to only have sex with that person.
The answer is either he is using his large muscles or his body heats up but I am not sure which one sorry hope I helped a little