The notion that athletes shouldn't have sex before they compete – as it could negatively affect their performance – is one of the longest-held superstitions in sports, but that myth has just been thoroughly debunked.
According to a new study that looked at hundreds of published papers examining the links between sex and sport, there is no plausible research that suggests sportspeople shouldn't get their freak on before game time.
"Abstaining from sexual activity before athletic competition is a controversial topic in the world of sport," says lead researcher Laura Stefani from the University of Florence in Italy. "We show no robust scientific evidence to indicate that sexual activity has a negative effect upon athletic results."
Despite the lack of evidence to explain why this myth still persists today, there's no questioning that the argument for abstinence goes back a long way.
As long ago as the 1st century AD, ancient Greek physician Aretaeus of Cappadocia wrote that a man's strength could be enhanced by the retention of semen, and the idea certainly stuck.
Even earlier than that, Greek philosopher Plato is said to have argued against Olympians engaging in sexual intimacy before competing in races.
The same thinking still holds in modern times, with coaches for the soccer World Cup disinviting players' partners from coming on tour.
And pop culture keeps the myth alive, with films like Rocky, where Rocky Balboa's boxing trainer warns his protege that "women weaken legs".
To see if there was anything in the scientific literature to support these ideas, Stefani's team sifted through more than 500 published scientific papers examining the ties between sport, sex, athletic performance, and abstinence.
Once they filtered out research that was irrelevant, they were left with just nine studies that were on topic – not an awful lot to support a notion that's been hanging around for longer than 2 millennia.
"We clearly show that this topic has not been well investigated and only anecdotal stories have been reported," says Stefani.
Of the nine relevant studies, which have been published over the past 60 years, the researchers found that none of the research had systematically addressed the question of whether sex affects sport performance.
"[T]here is no evidence of a methodical investigation of the possible differences by gender, or intensity, or the type of the sports practised," the authors write. "In most of the few manuscripts identified, males are more frequently investigated than females."
In fact, to the extent that we can draw any kind of conclusion from the published research, the consensus seems to be that sex before sports is more of a positive than a negative when it comes to performance.
"In general, there is a global positive impact of sex the night before competition on athlete's performance," the authors write. "Especially from the psychological point of view, sex has a relaxing effect, which may help to relieve competition stress in endurance (marathon) or concentration (archery or pistol shooting) sports."
Still, the researchers warn that the somewhat scattershot nature of the studies so far suggests that we can't really take away any general, reliable truths about the relationship between sex and sporting performance.
All we can really say is that there's no clear evidence to suggest that the former detracts from the latter, provided athletes make sure they get a good night's sleep before they compete.
"The present review demonstrates that sex activity in sport is poorly investigated in both males and females," the authors explain. "However, the data available do not really support the misconception that sex activity can produce a negative effect on the athlete's performance."
"Anecdotal experiences sustain, on the contrary, a positive effect of performance if sexual activity is undertaken at least 10 h before sports competition," they add, "and particularly if it is not associated to incorrect life style habits such [as] alcohol and drugs abuse, and smoking."
The findings are reported in Frontiers in Physiology.