From the ancient Greeks to modern soccer World Cups and the Olympics, there has been an enduring belief by some athletes and coaches that engaging in sexual activity before athletic competitions may be detrimental to performance. But is there any truth in this?

Rocky Balboa’s gnarled boxing manager Mickey once stated: “women weaken legs”. The origin of this belief probably relates to the idea that semen contains a cerebrospinal substance – (as proposed by the ancient Greeks) – or divine energy, as suggested by traditional Chinese medicine.

In the 1st Century AD, Greek physician Dr Aretaeus went as far to say a man’s strength could be enhanced by the retention of semen.

Some 2,000 years later, it’s not uncommon to hear of coaches and athletes who still believe avoiding sex can improve performance.

During the 1998 World soccer cup, the then English coach, Glenn Hoddle, famously forbade his players from engaging in sexual intercourse for the month-long event.

Unfortunately for the English, the misery of a poor world cup Cup campaign was compounded by no sex for a month!

But it’s not just tyrannical coaches banning sexual activity: many athletes practise self-abstinence and believe they can conserve strength and energy levels by not having sex before a competition.

While it seems unlikely that there is essential energy in a teaspoon of semen, some athletes have been known to avoid sex as a means of increasing frustration and consequently aggression.

As stated by the 1,500m and one mile runner Marty Liquori: “Sex makes you happy. Happy people do not run a 3:47 mile.” For this reason, some boxers and athletes have been known to avoid sex for up to a month before a big fight/competition.

But, what does the science say? Not surprisingly, there is very little scientific research on the effects of sex on athletic performance.

On one hand, it is not seen as a subject for serious study, and; on the other, it’s difficult to impose the strict controls necessary for rigorous research – how does one ensure that every participant performs their sexual activity at the same duration and the same intensity every time?!

I am only aware of four studies – including this one relating to cycling – that have tried to scientifically investigate the effects of sex on subsequent athletic performance; interestingly, all have investigated male performance (despite the participation of females in the sex!).

These studies have investigated factors ranging from six days of sexual abstinence to sex the night before competition, and all have concluded that there is no detrimental or beneficial effect of sexual activity before competition on subsequent athletic performance.

While sex itself is unlikely to be problem for athletes, chasing sex may be! It’s well known that sleep deprivation and alcohol/drug consumption can affect athletic performance.

Placing curfews on athletes, and avoiding late night/early morning socialising, is probably a wise strategy to maximise athletic performance.

But we must always take into account the important effects of belief on athletic performance – if an athlete believes sex will harm athletic performance, there’s a good chance it will.

But most athletes can be confident there’s no “divine energy” in semen and that, as long as they’re getting plenty of sleep and not performing hours of sexual gymnastics, a little sex is very unlikely to impair their athletic prowess.