Running is a journey of discovery. Not just of running routes and new places but of your own human body.
Over the years as a runner, family doctor, coach, and health expert for magazines and online communities, I have been asked literally hundreds of running-related health questions. In my book Run Well, I provide straightforward, science-based answers to many of them. Excerpted here are a few about sex and fertility that many are embarrassed to ask.
Will running improve sexual performance?
Studies on sexual performance rely on surveys and self-reporting, so there is always the risk that people don’t give accurate answers to questions about their sex lives and exercise habits. One of the larger, more recent studies carried out by the University of California in 2019 surveyed around 3,900 men and 2,200 women with an average age of over 40 to determine whether more cardiovascular activity (running, cycling, and swimming) each week reduced the likelihood of sexual problems. It found that men doing more cardio exercise each week reported less erectile dysfunction and women exercising more vigorously suffered less sexual dysfunction, too, with easier arousal and better orgasm satisfaction.
In sum, more exercise suggests greater sexual performance and satisfaction. The reasons for this are unclear, and many factors, both psychological and physical, will have a role, but improved circulation may play a part. Erections rely on an increased blood flow to the penis, and women’s genitals become engorged with blood during arousal. Remember too that conditions such as high blood pressure, obesity, and Type 2 diabetes are all causes of erectile dysfunction, which regular running can help to counteract.
So for a great sex life, you are well justified in spending plenty of time in your trainers!
Can running increase my sex drive?
There are many causes of a low sex drive or libido. While running can’t help reduce some of them, such as pain during intercourse, neurological diseases, and side effects of medications, it can help counteract many others. A low libido is often linked to mental health problems, such as anxiety and depression, and we know that regular exercise can help alleviate and treat these. Running is a useful tool for managing daily life stress and fatigue, both of which can have a significant effect on how keen you are to have sex. Low self-esteem and poor body image can lower libido, and running has an amazing ability to help people build confidence through goal setting and improving their relationships with their bodies. Regular running is a healthy lifestyle choice and reduces the risk of developing medical conditions that can affect libido, including high blood pressure, obesity and Type 2 diabetes.
Will sex the night before a race help my performance, or am I better off abstaining?
In the past, conventional wisdom held that having sex before a sporting event could decrease performance, and that a degree of sexual frustration would lead to a more aggressive, competitive, and successful performance. As a result, many individuals have been advised against or even prevented from having sex before important events. Research in this area is generally of low quality and mostly involves male participants. There seems, however, to be little evidence to support the theory that sex negatively impacts performance. One study showed that there is no negative effect if the sex occurs at least ten hours before the exercise test, but there is a negative effect if it occurs less than two hours before exercise.
It seems reasonable to presume that a late night with hours of sex might not put you in the best physical shape for an endurance event the following morning, due to expended energy and little sleep. However, a 2017 survey of over 4,000 Brits by online adult-toy business Lovehoney revealed that the average time for sex in the UK is 19 minutes (ten minutes of foreplay and nine minutes of intercourse), which would burn around 70 calories and not put too much of a dent in your energy or sleep.
If pre-race anxiety levels are high, sex can be relaxing and aid sleep, so potentially this could improve performance. There’s some evidence that the female orgasm lowers pain thresholds, which, if that effect lasted long enough (and we don’t know if it does), could be handy when you’re hurting in the toughest parts of a race the next day. They say never try anything new on race day, and you could add the night before race day, too. It’s not the best time for new sex positions if you want to avoid a muscular injury. All in all, it’s an individual thing—do what works for you and have fun with the trial-and-error testing.
Will running affect my fertility and sperm count?
A 2017 study from Iran concluded that exercising three times per week can improve sperm quality and numbers, and that moderate intensity exercise showed the most benefit. There were no changes in sperm in the control group that didn’t exercise. This sounds encouraging, but it’s wise to consider the limitations of this study. People in all the exercise groups lost weight, so we don’t know whether the sperm improvements were due to weight loss or exercise. It’s also worth noting that the people in the study didn’t exercise prior to taking part, so we can’t automatically assume that current runners could improve their sperm counts by running more.
There have been studies showing that excessive exercise can reduce sperm counts. This is particularly frequent in long-distance cycling, possibly due to reduced blood flow from saddle pressure and an overheating of the scrotum, which may be relevant to endurance runners, too. The jury is still very much out on how much of what type of exercise will have the most benefit on sperm production or whether this will actually lead to successful pregnancies. For now, it seems reasonable to say that including moderate amounts of regular running as part of a healthy lifestyle may improve—and won’t decrease—your fertility.
Should I stop running while I try to get pregnant?
No. This is a perfect time for you to optimize your health. Regular exercise is a vital component of a healthy lifestyle. There’s no evidence that the high-impact nature of running will reduce your risk of conceiving or increase your risk of miscarriage.
You need to be having regular periods to conceive, and sometimes women who are overtraining and/or underfueling may have amenorrhea (an absence of periods). You should be assessed by a specialist if this is the case for you. You will probably be advised to stop or reduce your running for your periods to return.
Getting pregnant can take time, especially as you get older—18 percent of couples ages 35 to 39 having regular sex haven’t conceived after a year of trying. This can be upsetting, and the stress-relieving benefits of running can be very useful.
Excerpted with permission from Run Well: Essential Health Questions and Answers for Runners (Bloomsbury Sport, 2021).