Does sex really sabotage race day? Here’s what the science says

We all have off days when races don’t go according to plan. Disappointing races are usually down to three different reasons. The most frustrating one is practicality, like a puncture thwarting your bike. Then there’s the psychological, like a lack of confidence during open water swimming. Finally there’s the physical, you may simply just run out of steam.

If tradition holds true, that latter physical category can also be affected by having sex. Sexual activity, no matter how brief, has typically been considered a big no-no the day before competition.

But is there any scientific basis preventing you from conquering the race course off the back of a bout of sexual intercourse? Could we have got it wrong, and could sex actually be beneficial the night before a triathlon?

It’s time to slip under our high-wicking sheets and find out…

What is the theory behind no sex before race day?

It stems from Roman and Greek times, when abstinence was considered the best strategy in achieving athletic performance and communion between body and spirit. This seemed at odds, of course, with the Ancient Olympics, where athletes would compete in pentathlon, chariot races, and wrestling stark naked.

This idea of sacrificing sex for sporting success pervaded generations with coach after coach believing that sexual frustration leads to greater levels of aggression, and that ejaculation would impair the athlete’s competitive edge.

Muhammad Ali was the highest-profile proponent of sexual self-restraint, reportedly abstaining from making love for six weeks before a big fight including his win over George Foreplay. I mean, Foreman…

• Does exercise help or hinder libido?

Is there any scientific basis behind no sex before race day?

One of the major reasonings behind abstinence before race day revolved around testosterone. Testosterone is the male sex hormone that’s important in myriad functions, including development of muscular strength, which is why athletes galore, including Lance Armstrong, injected testosterone. Vis-à-vis, the ideas was that ejaculation leads to lower testosterone levels, which leads to reduced muscular strength.

• Testosterone: increased levels found to improve a female athlete’s performance significantly

As I said, that’s the idea. But one that’s not supported by the literature, with numerous studies finding no difference in testosterone levels after sex.

A 1968 study also showed that female athletes’ performance wasn’t impacted by sex. Fourteen athletes performed a handgrip test either the morning after nocturnal sex or six days after, with neither having a detrimental impact on results.

Then again, a 1995 study by Boone and Gilmore showed that sexual intercourse prior to competition can impact physical parameters around endurance sport.

The subjects had sex either 10hrs or 2hrs before a cycle ergometer test, the authors showing that it’s fine for a romp 10hrs before but with only 2hrs to go, maximal aerobic power was down while pulse rate was up. (How long the sexual intercourse rolled on for is unclear but presumably not of Sting proportions.)

Despite starting the test under sex-induced physical stress, however, there were no performance differences between the groups. But it does suggest that abstinence on race morning is the safest bet.

And in our experience, race morning isn’t the friskiest of times, unless you’re particularly turned on by the thought of splashing about with 100 other neoprene-clad athletes, of course. If so, maybe have a word with your local therapist!

The subjects had sex either 10hrs or 2hrs before a cycle ergometer test, the authors showing that it’s fine for a romp 10hrs before but with only 2hrs to go, maximal aerobic power was down while pulse rate was up

Does the timing of sex matter more?

Well, a 2000 study in the Journal of Sports Medicine and Physical Fitness does support that 2hr sexual sanctioning. Fifteen high-performing athletes took part in a two-day experiment and were asked to abstain from sex for at least 24hrs before the study began.

On day one, they then completed a stress test on an exercise bike in the morning, followed by a mental test to measure concentration in the afternoon, and then a second stress test on the bike in the afternoon.

In between the mental test and the second stress test, blood samples were taken to measure testosterone levels. They then had sex with their usual partners and repeated the tests the following day.

Again, there were no performance changes or testosterone changes but the researchers did note a slightly higher heart rate post-sex, suggesting that “the recovery capacity of an athlete could be affected if he had sexual intercourse approximately 2hrs before a competition event”.

• How triathletes can harness their hormones for optimal performance

Can sex have a positive impact on triathlon performance?

Empirical data isn’t extensive, but relatively recent psychological-based studies have suggested that coaches are beginning to turn the other cheek.

Why is down to a number of reasons, including that the duration of sexual intercourse is nowhere near long enough to result in fatigue, and that it can have a calming impact. Enjoying adult pleasures has a relaxing effect.

On the other hand – or in the other hand if a partner’s absent! – frustration at limiting one’s desire to have sex is arguably more detrimental.

There’s also a link between sexual satisfaction and a higher quality of life, while prolonged abstinence can lead to depression. Equally, there’s a clear link between regular sex to the same partner and better mental health, says the literature.

Ultimately, not surprisingly, sex before athletic extersion is a subject where studies are limited and standardisation of protocols is erratic, so seeking a definitive conclusion is hard – so to speak.

But it seems that sex actually has a positive relaxing effect and is absolutely fine, though maybe refrain on race morning.