Legend has it that Muhammad Ali would refuse to have sex for six weeks leading up to a boxing match. The theory was that by denying himself sexual release, testosterone would build in the body. This testosterone would then make him more aggressive, and that aggression would push him to peak performance level, especially in a combative sport like boxing. More recently, some World Cup soccer coaches banned sex—or certain variations of sex—fearing their players would be physically exhausted before the tournament.
These theories, however, have been disputed by scientists for years, and a recent study published in Frontiers of Physiology just cemented more scientific evidence against them. The study looked at hundreds of relevant—not anecdotal—investigations into the effect of sex on athletes and determined that sex does not take a negative physical toll, unless an athlete has sex less than two hours—a far cry from six weeks—before competition. (The study did not assess the effects of masturbation.)
In fact, evidence suggested sex might have a positive benefit on athletic performance if it occurs at least 10 hours before competition. Rhonda Rousey, fighting legend in the making, has said she has "as much sex as possible" before her matches. Seems to work for her.
From: Esquire US