According to the U.S. Department of Health and Human Services (HHS), "physical activity is an important part of maintaining healthy weight, losing weight, and keeping extra weight off once it has been lost."
The HSS recommend at least 150 minutes of moderate-intensity exercise every week, but less than 25 percent of adults manage to hit this target.
Where does sex fit into this?
Well, sex is good for our health, it burns calories, and it makes us happy. You are, of course, unlikely to burn as many calories between the sheets as during a heavy gym session, but exercise alone may not be the panacea for weight loss we give it credit for, according to a recent study.
So, get ready to look at the obvious and some of the more surprising reasons why sex should be firmly integrated into our plan to reach and maintain a healthy weight, regardless of whether you are a gym buff or not.
Sex is exercise
In 2013, Prof. Antony D. Karelis — along with colleagues from the Université du Québec à Montréal in Canada — studied exactly how many calories we burn when we get our groove on.
Prof. Karelis explains in his article in the journal PLOS ONE that only a handful of studies have attempted to shine the spotlight on the physiological effects during partnered sex with human subjects. All previous studies showed an increase in heart rate.
For his study, Prof. Karelis worked with 21 heterosexual couples, aged between 18 and 35.
The couples were asked to have sex once per week for a period of 4 weeks, while wearing an activity tracker that allowed the research team to calculate how much energy they spent each time.
A sexual encounter included foreplay, intercourse, and at least one orgasm by either partner, then "ended at the couple's discretion," as the authors explain.
Here is what the team found.
Men burned on average 101 calories and women 69 calories when they had sex. The average intensity was higher than walking but lower than jogging, Prof. Karelis explains, putting it firmly in the category of moderate-intensity exercise.
This means that each time we have sex, it counts toward our 150 minutes of weekly exercise recommended by the HSS.
If that's not appealing enough, the data revealed more.
'More pleasant' than a gym workout
The range of calories burned during sex varied considerably. At the lower end, men burned 13 calories and women 11.6, while at the top of the range, men shifted 306 calories and women 164.
Let's look at these numbers into the context of how long each sexual encounter lasted. While the average duration of foreplay, intercourse, and orgasm was 24.7 minutes, the actual time the couples spent having sex ranged from 12.5 to 36.9 minutes.
Whether the top calorie-burners had more vigorous sex or just took their sweet time isn't clear from the data, but we can draw some conclusions. If we want to increase our calorie loss during sex, we can either get more actively involved, keep at it for longer, or a combination of both.
Prof. Karelis also compared sex with regular gym exercise. He found that men burned between 149 and 390 calories during a 30-minute, moderate-intensity session on the treadmill, while women burned between 120 and 381.
When asked to compare the two activites, all of the men and 95 percent of the women in the study said that sex was more pleasant than pounding the treadmill.
So, we are not only making considerable headway toward reaching our 150-minute weekly exercise goal when we have sex, we also stand to gain more pleasure than from a gym visit.
Exercise may not equal weight loss
While some may argue that a study on healthy, young individuals may not be representative of the general population, the participants included a wide spread of weight categories.
Body mass index (BMI) for men varied between 19.5 and 31, putting at least some of the men in the overweight and obese category. For women, the range was from 16.9 to 26.6, meaning some of the women were underweight and some were overweight.
The study doesn't reveal anything about the participants' weight during the 4 weeks they took part. But if you're looking to shift some pounds, exercise alone may not be the answer to weight loss we once thought it was, as we reported last week.
Researchers from the University of Bangor in the United Kingdom found no discernible weight loss in women who had taken part in three sessions of circuit exercise training per week for either 4 or 8 weeks, despite burning around 3,400 calories in total during this time period.
On the contrary, the team identified changes in hormones that control appetite in overweight and obese study participants after exercise.
"[...] Someone undertaking more physical activity may experience increased appetite as a result," senior study author Hans-Peter Kubis, Ph.D., explains.
Sex might fill a useful gap here because hormones released during our amorous experiences cause us to eat less.
Sex curbs food intake
The "love hormone" oxytocin is produced in the hypothalamus in our brain as well as in our gastrointestinal tract, and it has been accredited with key functions in sex, empathy, relationship-building, childbirth, and breast-feeding.
Oxytocin levels shoot up when we have sex – specifically, when we experience orgasm. But that's not all the love hormone can do.
Dr. Elizabeth A. Lawson — from the Neuroendocrine Unit at Massachusetts General Hospital in Boston — explains in an article in the December edition of Nature Reviews Endocrinology that "experiments in rodents, nonhuman primates and humans consistently show that oxytocin reduces caloric consumption."
She adds that men ate fewer calories, particularly in the form of fat, after receiving 24 international units (IU) of oxytocin in a nasal spray in one study.
"The authors found that oxytocin reduced consumption of a postprandial snack, particularly chocolate cookies," Dr. Lawson explains.
It's important to note that oxytocin doesn't stick around in our bodies for very long. Within 2–8 minutes of being released, half of hormone will be gone.
The after-effect of a single sexual encounter on our food intake will therefore only ever be transient. Still, every little helps, and a temporary curb on eating after sex is sure to contribute to overall weight loss.
Sex and weight management
Now that we've looked at the benefit of sex when it comes to burning calories and temporarily putting a halt on eating, how likely is it that we are going to lose weight by having sex?
That probably depends on how easy it is to incorporate sex into your personal schedule. Finding time to be romantic sounds easy, but the stark reality of busy lives make it less tenable for some.
However, it is worth reminding ourselves that sex has a plethora of health benefits, and, unlike a gym visit, you don't have to stray far from your bedroom — or other location of personal preference — to make it happen.
So, if you are looking to shed a few pounds in the lead up to the peak holiday season, why not make the time to spend with your partner, enjoy sharing some intimate moments, and bask in the full effect that all that oxytocin and calorie loss will hopefully have on your scales.
You might find that your 2018 diet plan will easily accommodate sex as an indispensable component.