A reader submitted the following question:

"Everyone says sex is a great form of exercise. But, realistically, how many calories can you actually expect to burn when you have sex?"

Great question! I, too, have often heard the claim that sex is one of the best forms of exercise that you can get; however, it doesn't seem to be as much of a calorie-burner as it's made out to be. Just how many calories are you likely to burn during an average sexual encounter?

In a recent study published in PLoS ONE, 21 heterosexual couples aged 18-35 had sex for the sake of science (I know--it’s a tough job, but someone has to do it). Each couple was in a monogamous, long-term relationship and, as part of the study, had sex in their own homes on four separate occasions. Participants were told to practice their “usual” activities and to avoid performance enhancers (e.g., Viagra). Each time they had sex, both members of the couple wore computerized armbands that kept track of the amount of energy expended. The armbands were supposed to go on as soon as foreplay commenced, and be taken off as soon as sex was over. For comparison purposes, each participant also took a 30-minute jog on a treadmill while wearing their armband in order to allow a direct comparison of caloric expenditures during sex and exercise.

Results revealed that there was substantial variability in how long sex (which included both intercourse and foreplay) lasted across couples, ranging anywhere from 10 minutes to 57 minutes (25 minutes was the average). So how many calories were burned in an average sexual session? For men, that number was 101 calories (4.2 calories/minute), whereas for women it was 69 calories (3.1 calories/minute).

How did sex stack up to jogging? Both men and women burned more than twice as many calories during their time on the treadmill as they did during sex. Across 30 minutes of jogging, men burned 276 calories (9.2 calories/minute) and women burned 213 calories (7.1 calories/minute). This tells us that, on average, people tend to exert more energy while exercising than they do during sex.

Of course, keep in mind that there was a lot of individual variability here, such that some participants actually burned more calories during sex than they did while jogging. Why is that? For one thing, some people spend a lot more time on sex than others (in this study, some couples spent almost 6 times longer on it than other couples!). For another, “sex” means different things to different people, so there's going to be a lot of variation in what activities people practice and how much effort is required. Then there's also the fact that everyone has their own unique body composition and metabolism, meaning everyone burns calories at different rates. We also need to keep in mind that this research focused only on young, healthy, able-bodied, heterosexuals, so we can't necessarily assume that the averages observed here would hold for other groups of people. Some people will burn more, while others will burn fewer calories.

With that said, the available research suggests that a young guy having heterosexual sex for 25 minutes could probably expect to burn in the neighborhood of 100 calories, while a young woman would likely burn closer to 70. To put this in perspective, a single can of Coca-Cola or Pepsi has 140 calories. Thus, to make sex count as a major part of one's exercise routine, odds are that both that time spent on sex and number of times it occurs would need to be increased...by a lot.

For previous editions of Sex Question Friday, click here. To send in a question for a future edition, click here.

Want to learn more about Sex and Psychology ? Click here for previous articles or follow the blog on Facebook (facebook.com/psychologyofsex), Twitter (@JustinLehmiller), or Reddit (reddit.com/r/psychologyofsex) to receive updates.

To read more about this research, see: Frappier, J., Toupin, I., Levy, J. J., Aubertin-Leheudre, M., & Karelis, A. D. (2013). Energy expenditure during sexual activity in young healthy couples. PLOS ONE, 8(10), e79342.

Image Source: iStockphoto.com

You Might Also Like: