Unbeaten American boxer Floyd Mayweather Jr has some advice for men, not on how to knockout their opponent in the ring but on how to prevent their testicles from hanging low.

He shared that the secret to keeping one's testicles high and tight for life is to wear tight underwear when sleeping. Ironically, he gave the advice to a few female friends on Showtime's All Acess - Mayweather vs Maidana. (https://www.youtube.com/watch?v=56hsFa7nbO0)

However, medical experts would disagree with Mayweather's advice.

The Underwear Expert pointed out that very tight undies could affect a man's sperm production. It cited Dr Rafael Lugo of the Methodist Hospital in Houston who said the test if skivvies are too tight is if the scrotum is tender. Men suffering from such kind of pain should see their urologist.