Compression in scrotum & penis during gym

Patient: Hello doctor,i started gym practice some 3 years back and everything was normal. after 1 year, i had to leave it for more than a year. now i have started the exercise again. but one problem has arised :during lifting heavy weights, my scrotum gets compressed and penis also contracts for some time. but everything goes to normal as soon as i reach home. it doesnt pains or anything else, just the compression. when i contacted the gym manager, he suggested to wear V shaped underwear, i got that too, but it still doesnt work. i still feel the compression.

Symptoms: Compression in scrotum & penis

Doctor: