In short, good news for athletes.
A belief that comes from afar
Still today, there are those who follow these archaeological footprints, perpetuating the ideas of the ancients: the coach of the Bosnian national football team, for example, has invited the players' partners not to follow them in Brazil for the 2014 World Cup. But searches in hand, it doesn't seem naive to assume that the team would have obtained better results if the players were in Rio in two.
False, but above all little studied
In any case, there was unanimous agreement on the definitive thesis: sex has more positive than negative consequences on physical activity.
If the beneficial impact on the body seems to be generalized, the greatest benefit is psychological: sex has a relaxing effect and helps relieve competitive stress, making it particularly beneficial for endurance sports and those requiring a very high level of concentration. Provided that sleep is not sacrificed to do so.
A rule: no rules
The same research has produced, among others, two other data sets of great interest: in particular for male athletes, masturbation would have an even more significant effect on the body than sexual intercourse, improving agility and physical strength; and to count more than anything else in the sex-sport relationship would be, once again, a psychological aspect: very simply, to think that your sexual activity negatively impacts on athletic performance leads to an actual drop in performance and thinking the opposite leads to an actual improvement.
Beyond popular beliefs, among coaches of professional athletes the agreement is (almost) total: the best rule is not to establish any rules, leaving the choice on sex before competitions to the individual athlete.