To get this data, the study authors created a survey that asked participants questions about their exercise habits and libido. The first part about exercise asked for information such as history of regular exercise, intensity of training (defined as the number of light, moderate, and hard sessions per week), duration of exercise (hours per session and total hours per week), and more. The second part asked questions about their sexual activity, arousal, desire, attraction, fantasies, needs for intimacy, and infertility issues.
The authors were able to use data from 1,077 respondents, and categorized the responses about libido into “low” and “normal/high.” Men who fell into the “low libido” category consistently stated that they lacked desire and that their sexual frequency was also low, even for those in relationships.
The findings: While the researchers weren't able to determine what specific number of exercise hours led to a dip in sex drive, many of the men with low libido noted that they competed in events that would require a lot of intense, long-term training, such as marathons and triathlons.
While the effects of intense exercise on women are well-known (think: issues like athletic amenorrhea, or missed periods due to intense training), this is one of the first studies to look into how workout habits can affect men. And study author Anthony C. Hackney, Ph.D., professor of exercise physiology and nutrition at University of North Carolina at Chapel Hill, is coining a term for the male equivalent of athletic amenorrhea: “exercise hypogonadal male condition (EHMC).” In short, guys who exercise a ton may not produce as much testosterone.
“It relates to energy availability,” Hackney tells Women's Health. “During periods of a lot of energy expenditure, your body views that as a short-term starvation scenario, so it tries to conserve calories. And conceiving a child takes a lot of energy, so it’s saying let’s stop producing as much testosterone since it’s not a good time to conceive.” And lower levels of testosterone can mean a dip in sex drive and fertility.
But unlike women, who exhibit more of a visual cue that over-exercising is taking a toll on hormones (read: lack of a period), men might not be able to pinpoint that something’s up. Some other potential signs? “If he’s starting to experience chronic fatigue or soreness, lasting up to two weeks after a workout, or starting to have a lack of motivation to do his workouts, he could be exhibiting some low testosterone,” says Hackney.
You guy’s best bet to up his sex drive and fertility is to cut back on gym time, but that can be easier said than done, of course, especially if he’s training for a competition. So Hackney recommends he at least try to lower the intensity of workouts. If that doesn't quite do the trick, he should lower the volume as well, meaning more rest days and fewer consecutive hours breaking a sweat. "In the context of exercise training, intensity is playing with fire," says Hackney. "Too intense, it will beat you up." And even if he does cut back, it can still take time (up to several months) for his testosterone and libido to return to normal levels.
The only way to really determine his testosterone levels is to get a blood test, but unless you’re doing so to test for fertility issues, that can be expensive and impractical. If it’s just his bedroom enthusiasm that’s lacking, try talking to him and asking him to ease up.
This article originally appeared on Men's Health US.