30-Second Takeaway

  • Many men believe that releasing sperm through sex or masturbation affects muscle growth and athletic performance.
  • Some research suggests having sex may improve your game by keeping you fit and relaxed; others show zero benefit.
  • Most studies have found that masturbation and sex don’t increase levels of testosterone, a hormone that fuels muscle growth.

Athletes have been divided about whether sex helps or harms muscle growth and athletic performance since ancient times.

The debate lingers among today’s most elite athletes. Just take two of the arguably best boxers of all time, Floyd Mayweather and Tyson Fury: It was reported that Mayweather—the undefeated 15-time world champion—didn’t go near sex before his anticipated fight against MMA superstar Conor McGregor. Meanwhile, the story goes that two-time world heavyweight champion Tyson Fury claimed getting after it seven times a day helped his success.

Who’s right? Let’s dig into the research.

About the Expert

Todd A. Astorino, Ph.D., is a professor of kinesiology at California State University San Marcos.

Does Releasing Sperm Affect Muscle Growth?

So far, science has not proven that ejaculation interferes with muscle growth. One argument among those who abstain is that releasing sperm (with a partner or solo) interferes with muscle growth because of its effects on testosterone.

There’s some evidence that testosterone may play a role in regulating your libido, your mood, your ability to store and burn fat, and muscle growth. That last one is a main reason why scores of men take supercharged doses of synthetic versions of testosterone in the form of anabolic steroids to boost muscle mass. (For the record, that’s definitely not something we recommend.)

Because of this connection, a not-insignificant number of men believe that semen retention can boost testosterone levels and support muscle-building gains. As evidence, they—along with proponents of the NoFap movement—point to a study published in 2002 that found testosterone levels in men peak 7 days into a sex-free streak (1). 

What most fapstronauts fail to notice is that on the eighth day of the study, after T spiked, no regular fluctuation was observed. There is no strong evidence to support that semen retention boosts testosterone.

A larger study (2) did find that masturbating may increase T, but more research is required.


Can Avoiding Sex Improve Athletic Performance?

Avoiding sex may impact your athletic performance in a few ways.

Sex might reduce aggression

One argument among men who refrain from having sex before a big game or gym session: when you release sperm, you also release the sexual frustration that breeds the aggression that could help you defend your goal or hoop.

Anger and frustration may build up in a man who is not sexually active, which potentially can be used to ‘fuel’ the subsequent physical effort, although this is more speculation than science,” says Todd A. Astorino, Ph.D., professor of kinesiology at California State University San Marcos.

Sex might reduce energy

And then there’s the actual effort of intercourse (and even masturbation). Some coaches believe it’s best to reserve that energy for the field—particularly if your midnight activity interrupts a good night’s sleep and leaves you groggy. 

That might explain why, in a study of 14 soccer players published in the Journal of Sports Medicine and Physical Fitness, men who had sex the night before their match ran an average of about 10% slower (3).

Another study of 15 male athletes compared stress tests two and 10 hours after intercourse. Researchers found it took longer for the heart rates of those who’d done the deed most recently to return to baseline (4).

A 2017 systematic review of 7 studies that looked at the impact of pre-competition sexual activity on athletic performance confirmed the recommendation that it may be best to schedule sex at least 10 to 12 hours before a competition, when it is less likely to affect things like grip strength, muscular endurance, hamstring flexibility, reaction time, aerobic power, VO2 max, cortisol concentration, and more (5).

More research is needed

However, large-scale studies on the effects of sex before competition are sparse. So unless you’re a pro athlete for whom winning or losing can lead to victory or heartache, Astorino says, chances are small changes in lab-based measures of performance will be meaningless for you.


The Case For Pre-Workout Sex

It sounds too good to be true, but a bedtime bang may help you get jacked and fit so you can deliver a stronger athletic performance.

Sex might boost fitness

Sex, the authors of one study say, can be considered another form of cross-training that conditions you for competition (6).

Sex might reduce stress

Another theory, put forth in a review of studies on the effects of sexual activity on sport performance, concluded that the impact of sex the night before competition may, in part, have to do with the relaxing effect of having sex or masturbating. It suggests that less stress ahead of a competition that requires endurance (like marathoning) or concentration (like archery) may help improve coordination and athletic performance. (5).

Sex might improve sleep and recovery 

Ejaculation can also send oxytocin levels soaring, which may help you relax and get better Zzz’s—a good thing when you’re hoping to make gains at an a.m. workout (7).

Top trainer Jeff Cavaliere has another theory: Hormone release after sex or masturbation can promote a more restful sleep, he says. If you get a more consistent restful 8 or 9 hours, he says that is going to lead to better recovery and an increase in muscle mass over time. Meaning? Better sleep equals more muscle growth—at least in his theory.


Do you lose gains when ejaculating?

Nope. There is no solid scientific evidence that ejaculating affects muscle growth or athletic performance. Most studies have found that masturbation and sex don’t impact testosterone levels. 

The Bottom Line

“While most existing research doesn’t distinguish between masturbation, intercourse, climax, and individual sports, most sex scholars agree that there is unlikely to be a significant impact of sexual activity on aerobic strength or strength performance,” says Astorino.

What’s more, at the end of the day, the effects of sex on athletic performance are, well, personal:

“Any athlete or exerciser needs to identify how they feel after sex and if it is truly performance-altering for them,” Astorino says.

So instead of scrutinizing your bedroom activities to perfect your performance, Astorino says, “It may be wise to look elsewhere: It is more important that exercisers focus on characteristics of their training regimens, nutritional habits, and recovery, as these will likely elicit greater changes in performance.”