The Rumor: Abstaining from sex before a race or big game will help you perform better

In the movie Rocky, Rocky Balboa's curmudgeonly trainer, Mickey, warned, "Women weaken legs." The implication, of course, was that sex can be detrimental to athletic performance, especially for men. But Mickey was hardly the first coach to say something like that. The ancient Greeks believed in forgoing sex before sports. Heavyweight boxing champion Muhammad Ali reportedly went six weeks without lovin’ leading up to a bout. Former Team England soccer coach Glenn Hoddle famously prohibited his players from doing the deed for the duration of the 1998 World Cup. And American running legend Marty Liquori proffered his stance on the matter thusly: "Sex makes you happy. Happy people do not run a 3:47 mile." Well, sorry to break it to you, fellas, but you probably missed out on a lot of between-the-sheets action for no good reason.

The Verdict: Having sex before an athletic competition won't hinder performance in the slightest

The driving belief behind the notion that sex is damaging to athletic performance has been that the act leads to a reduction in testosterone levels and aggression, two things that can be beneficial when it comes to excelling on the field, track and court. The only problem: All evidence shows that isn't true.

In a 1995 study, Dr. Tommy Boone, a fellow with the American Society of Exercise Physiologists and author of the book "Sex Before Athletic Competition: Myth or Fact?," measured the treadmill performances of men who had sex 12 hours previously against the performances of men who had been (in Shakespeare's words) "chaste as ice" the night before. Boone found that there was no discernible difference in aerobic power, blood pressure or performance between the two groups. "If athletes have engaged in sex prior to athletic competitions for years -- which they have and continue to do -- what is the point of abstinence?" Boone rhetorically asked Competitor magazine in 2012. "Clearly, sex is part of life -- including the athlete's life."

But won't taking that trip to Funkytown on the eve of competition drain valuable energy? According to Boone, even if you had vigorous sex for a full hour -- and we're talking kinky 50 Shades of Grey-type stuff -- you'd still only burn an easily replenishable 250 calories or so. And since you're not Christian Grey, most of your sexcapades probably last considerably less than an hour and only burn about 50 calories -- the rough equivalent of walking up a couple flights of stairs. Eat a banana and you've refueled.

A 2000 study of cyclists conducted by researchers at University Hospital in Geneva, Switzerland, also found that sex the night before athletic activity had no harmful consequences for performance -- though the experiment did conclude that performance wasn't optimal for two hours after sex. Translation: Sex is not the best way to warm up right before you compete.

In a paper published in The Clinical Journal of Sports Medicine, Olympic triathlete Samantha McGlone and Ian Shrier, Ph.D., comprehensively overviewed all studies on the subject to that date. Their conclusion: The overwhelming evidence indicates that sex doesn't affect performance in any way physiologically, and should be a judgment call on the part of the athlete. "If athletes are too anxious and restless the night before an event, then sex may be a relaxing distraction," McGlone and Shrier wrote. "If they are already relaxed or, like some athletes, have little interest in sex the night before a big competition, then a good night's sleep is all they need." In other words, it's totally your call -- and psychologically, whichever option you choose will probably help you if you believe it will.

Dr. Pamela Peeke, a spokesperson for the American College of Sports Medicine, seconds McGlone and Shrier's stance that athletes can benefit from the soothing effects of sex. "For both men and women, when you have sex, your tension goes down and you feel more relaxed," Peeke told ThatsFit. "Overall, sex is good for the body." Women might even enjoy an ancillary benefit: According to Peeke, sexual stimulation in women can lead to the release of a pain-blocking chemical that will "decrease overall muscle tension that an athlete might be experiencing, which may allow her to engage in physical activity at a higher, more intense level."

Still, while all evidence suggests that there's no harm in turning on a little Barry White and getting it on the night before running your first New York City Marathon, that doesn't mean you should stay up until 4 a.m. trying to have sex. Most of the activities associated with the pursuit of sex -- including alcohol consumption, lack of sleep and smoking -- most definitely can have adverse effects on the body, including dehydration, lack of focus and reduced lung capacity. So if you're in a relationship and feel like a little tension-relieving, pre-competition roll in the hay, go for it. But if you're going to need to wine and dine someone for several hours before doing the deed, maybe take a pass.

As Mickey might say if he were armed with this new information, "Rocky, it ain't women that weaken the legs. It's those bums booze, smokes and sleep deprivation. Bums, I tell ya, Rock, bums!"

Will having sex before you compete hurt you or help you? Here's how to find out:

1. The night before your next race or competition, ask yourself whether you feel like having sex or just going straight to sleep.

2. Do that and see how it affects your pursuit of your competitive goals.

3. If you aren't happy with the results, try the opposite scenario next time you compete. Either way, you get to have sex at least once.

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