How much does sex really contribute to health, and what’s the most dangerous position?

Data collected from 1956 to the present shows how sex affects fitness, what common injuries to look for, and how the "doggy style" position affects the spine. The findings might surprise you.

Couple in bed [file photo] (photo credit: INGIMAGE)
Couple in bed [file photo]
(photo credit: INGIMAGE)

Sex is considered one of the simplest and most enjoyable ways to move the body. It's likely that most people would prefer it over lifting weights at the gym or sweating outside, and for many, it doesn’t feel like hard work that requires effort. The question of how much sex really contributes to fitness fascinates many people, which is probably why it’s been studied extensively in diverse academic institutions worldwide.

Now, a new and first-of-its-kind study conducted by Spanish researchers from the University of Almeria tries to sort out all the data collected on the subject to explain in a nuanced manner when the act is done and how much it really affects our physical fitness. The study in question is a systematic review that examined 18 previous studies conducted between 1956 and 2020. It included data on 349 people: 264 men and 85 women.

Everyone has sex differently and many factors affect its contribution to health: duration, intensity, positions and more. In general, Spanish researchers have seen that in many cases sex is considered to be moderate-intensity exercise like jogging, swimming, or cycling at a leisurely pace.

In the studies examined, people from different backgrounds and with diverse sex habits participated, although more men than women joined. Studies were conducted using different methods, but the common factor was that they weren’t satisfied with questionnaires, and instead asked people to have sex while physical traits were monitored including pulse, blood pressure and blood oxygen level. This might explain the low response among women. Researchers also examined pressure on the muscles and joints during and after sex.

How many calories are actually burned

Before we know the conclusions of the study, it’s important to dwell on a statistic that greatly affects the contribution of sex to health, which is duration. Everyone has different sex habits and another study on the subject shows how wide this range is. The study included data on 500 couples who measured act time, with the figure ranging from 33 seconds to 44 minutes, with an average duration of 5.4 minutes.

Of course, the logic is that the longer you "hold on" the more calories will be burned, but researchers from the University of Almeria emphasize that on average, couples burn only about 100 calories during sex. To compare, a slice of bread has about 264 calories.

 HER TOUCH in Jerusalem apartments:  master bedroom. (credit: Renen Dizdar) HER TOUCH in Jerusalem apartments: master bedroom. (credit: Renen Dizdar)

The researchers also found that the heart rate increases on average from 90 to 130 beats per minute during intercourse, while during orgasm a record of 170 beats per minute can be recorded. To compare, at rest the heart rate of healthy people ranges from 60 to 100 beats per minute.

Dangerous and safe positions: Not what you thought

Sex is for pleasure, not to burn calories or get buff. Along with pleasure, sex has many significant health benefits, yet injuries are possible. Besides sexually transmitted diseases or unwanted pregnancies, there can be orthopedic problems.

Spinal and lower back injuries were the most common in intercourse, as a result of increased and repeated use of the leg muscles. Missionary is the most dangerous pose for both parties involved because it causes significant pressure on the spine and lower back.

So what’s the most "healthy" position for your body? Academics actually recommend "doggy style" to avoid injuries and strain on the skeletal system. Also, shoulder injuries are common during sex, as both partners often try to adjust to their partner, so shoulders might lock. This is also true of the "big spoon" if you cuddle with your partner at the end.

Researchers also cautioned and stressed that not many studies have been conducted in an orderly and thorough manner on this important topic. Many focused on the effect of sex on men, and no one examined homosexual relationships, for example. Also, most research is outdated; very little has been conducted in the last decade. Researchers stressed that this is an opportunity for more scientists to use the latest technologies to accurately measure how one of the most important and enjoyable actions in our lives actually affects our health.