It's the question you've always wanted to know about, but weren't quite brave enough to ask.
Does sex count as proper exercise? Well, you're about to find out!
As we all know, nothing says sexy quite like a bit of maths and science. That's why we've put together this fun, interactive calculator to let you know exactly how much of an effect your sex life is having.
Just put in your weight, gender and average 'session time' (no cheating!) and we'll let you know how many calories you're burning in bed.
While the results from our calculator will give you a rough estimate of how much exercise you're actually doing during sex, we can't stress enough that this is just a bit of fun.
You shouldn't start counting your results as part of any weight loss or fitness plan you're currently undertaking.
If you're after a truly accurate calculation, there are lots of other factors to consider. For example, some positions require more exertion than others. We're sure you don't need us to explain this concept any further - we'll leave it to your imagination!
As a matter of fact, yes. Fans of the TV show Masters of Sex will be familiar with the work of scientists William H. Masters and Virginia Johnson, who in 1966 began a pioneering study into how the human body responds during sexual intercourse.
Another study, carried out by scientists at the Universities of Quebec and Montreal in Canada, compared the amount of energy used during sex and during 30 minutes on a treadmill. They concluded that their findings were enough to class sex as a legitimate form of exercise.
Of course, these studies have their limitations too. Ultimately, they've only really looked at couples in a laboratory setting, where the people involved have been hooked up to machines or worn special monitors, all of which could have made them behave differently to how they would normally.
Until someone can get data from people in their usual environment, one where they forget they're part of an experiment, the true effect of sex on the body will remain something of a mystery.
As well as putting together this clever little calculator, we've also been looking at how falling in love can be good for your health.
And, if exercising with a partner sounds like fun to you, we've put together some exclusive couples workouts that will allow you to get fit together. That's assuming you want to leave the bedroom, of course!