Your Long Runs Could Be Killing Your Sex Drive

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Before you kill yourself trying to break a marathon record, consider the latest research published in Medicine and Science in Sports and Exercise. There appears to be a (somewhat) inversely proportional relationship between length and intensity of endurance exercise and male libido. That means your longest, hardest training sessions may leave you too depleted for sex. Bummer, right?

“Research by our group and others has shown that men engaged in chronic endurance training are more likely to induce low levels of testosterone, a hormone associated with libido,” says Dr. Anthony Hackney, the study’s lead researcher from the University of North Carolina at Chapel Hill. According to the survey results compiled and analyzed by Hackney’s research team, men who racked up more than 10 hours of training per week, and those whose training intensities were self-reported as greater than 70 percent of their VO2 max, were most likely to be categorized as having a low sex drive.

But before you swear off exercise completely (because, who could blame you, really?), the good news is that low to moderate levels of endurance exercise don’t appear to negatively impact sexual health — at least to a noticeable degree. And if you’re more of a strength-focused athlete, you could be completely in the clear. “Strength-trained athletes work very hard, but the nature of their training doesn’t usually result in as large a volume of training dosage,” Hackney says.

In other words, training for a 5k or hitting a CrossFit workout probably won’t put a dent in your desire, but if you spend year after year logging hours of training for marathons, Ironmans, and other extreme endurance races, you may have the sex drive of a much older man. The combination of regular, exhaustive exercise and reduced testosterone levels don’t add up to extreme acrobatics in the sack.

Of course, Dr. Hackney and his team didn’t set out to fix any one man’s personal sexual performance deficits. Rather, the team aimed to link high levels of chronic male endurance training to possible fertility problems — and low sex drive is, in fact, a fertility problem. Sorry guys.

While it’s fairly common knowledge that highly trained female athletes, particularly those with low body fat percentages, can experience problems with fertility, this is the first study of its kind that indicates highly trained male athletes may also experience similar problems — a fact couples and doctors need to be aware of.

“We hope clinicians will recognize the need to ask questions about what a man is doing with his exercise when they counsel couples who are seeking help with infertility issues,” Hackney says. “Exercise is wonderful. I truly believe that ‘exercise is medicine,’ but if someone exercises, they need to recognize this doesn’t prevent them from experiencing some negative health consequences.”