London - The ancient Greeks believed athletes should avoid sex before sport, but modern Olympians and scientists are torn over the merits of in-competition coitus and whether abstinence enhances performance.
For years coaches and athletes have practiced abstinence the night or even weeks before a big event, although all bets are off when the medal ceremony is over - 150 000 condoms are handed out to the 10 500 athletes competing at the London Games.
Boxer Muhammad Ali reportedly went without sex for 6 weeks before a big fight, and during the 1998 soccer World Cup, the then English coach Glenn Hoddle famously forbade his squad from having sex during the month-long event.
American Marty Liquori, the world's top 5000m runner four decades ago, was once quoted as saying: "Sex makes you happy. Happy people don't run a 3:47 mile."
Experts say the long-standing "no sex before sport" myth has yet to be explored fully, however. Most research has been based on the physiological impact and, so far, having sex has not been found to reduce physical strength, power or endurance.
"When we test people in the lab, we are examining 'tests of performance' but in competition, psychology very likely plays a much more important role," said Ian Shrier, a professor in the department of family medicine at McGill University in Canada.
"Those who claim it decreases performance usually say it is because it decreases focus or aggression or tension. There are no studies that have examined this."
A review of scientific studies on the issue published in the Clinical Journal of Sport Medicine suggested sex the night before competition has no effect on physiological test results.
In one study, 14 married male former athletes were given a maximum-effort grip strength test the morning after coitus, and the same test after at least 6 days without sex. The results showed neither strength nor endurance of the flexing muscles was adversely affected by sex the previous night.
A follow-up to this study was conducted by researchers at Colorado State University on 10 fit, married men aged between 18 and 45. In their tests for grip strength, balance, lateral movement, reaction time, aerobic power, and VO2 max - a measure oxygen efficiency - sex appeared to make no difference.
A third study conducted in 1995 found having sex 12 hours prior to a fitness test had no significant effects on maximal aerobic power, oxygen pulse or blood pressure.
A theory that sexual frustration makes people more aggressive, and that ejaculation draws testosterone, an athletic performance-related hormone, from the body, has yet to be scientifically proven.
"Even if that theory is correct, most people currently believe there is an optimal level of aggression or focus - too little and you don't do well, too much and you don't do well," said Shrier.
Martin Milton, an expert in psychotherapeutic and counselling psychology at the University of Surrey, said the effect of sex would depend very much on who's doing it, how often, for how long and in what way.
"If it's 'up all night swinging from the rafters' type sex we're talking about, then obviously the athlete is not going to be getting enough sleep or rest and their mind isn't on the job," he said in a telephone interview.
"So that might well be more the issue than whether or not being involved in a short period of sex might be detrimental to someone's performance."
At the London 2012 Games, while there might not be much sex being had, it's certainly being talked about.
Even London Mayor Boris Johnson is getting in on the act, telling reporters last week he wants the Olympics to "inspire a generation" not "create a generation".
The Australian team hit the headlines when its committee decided shooter Russell Mark could not share a room in the athletes' village with his wife and fellow shooting competitor Lauryn Mark.
Mark, a six-time Olympian and double trap gold medallist in the 1996 Atlanta Games, said he was planning to sneak off in the night to see his wife.
The Australian Olympic Committee played down the furore, saying allowing the couple to share would inconvenience other female athletes.
In Italy, sports fans have been fascinated by the pre-race activities of the nation's best-known sportswoman, Federica Pellegrini, who won a gold medal in the 200m freestyle at the Beijing 2008 Games.
Her boyfriend, fellow Italian swimmer Filippo Magnini, told magazine Chi they would be avoiding sex before Pellegrini's London races.
Pellegrini, 23, who once appeared naked and painted in gold on the cover of Vogue, was not so sure.
"Abstinence!" she said. "Are you mad?"