When it comes to burning calories, if you give people the choice between an hour on a stair climber or pretty much any amount of time having sex, chances are they’re going to choose the workout that happens in the sheets and not in the gym. But just how many calories is the average horizontal sweat session burning?

HuffPost asked experts to give us the lowdown on the physical benefits of sexual activity. Here’s what you should know about the calories you torch and how else getting busy can boost your physical health:

Yes, researchers actually have data on how many calories a person burns on average during sex…

Antony Karelis, a professor at the department of exercise science at the University of Quebec at Montreal, was part of a research team that conducted a study with 21 heterosexual couples examining energy expenditure during sex. Because no such data existed, Karelis was specifically interested in exploring the subject in units of calories burned, so it could be compared to traditional exercise.

Each couple was instructed to have four sexual encounters over a month and wore armbands that collected data like body temperature. The information then was used in conjunction with height and weight to calculate the calories burned in each session. The mean number of calories burned during sexual activity for men was 101 kCal and 69.1 kCal for women. Researchers also calculated a per-minute figure: men burned 4.2 calories per minute and women burned 3.1.

…But ultimately it varies from couple to couple.

Karelis’ research only included couples who were straight, healthy, non-obese and in their early 20s, among other restrictions. So while the study offers a great foundational place to start when understanding the energy expenditure of sex, it can’t deliver accurate caloric data for queer couples, older couples or other populations who weren’t included.

But even without specific data, we know that not everyone burns calories at the same rate during sexual activity, anyway. Men typically burned more calories than women in the study, given that their body mass was generally larger and “the bigger you are, the more you’re going to expend,” Karelis said. But this generally holds true of anyone with a larger body mass index (BMI), regardless of sex, he added.

Your health can affect how you burn calories during sex.

Those with chronic illnesses like cardiac diseases, cancer or diabetes, as well as those who live a sedentary lifestyle, may burn fewer calories from sexual activity.

“Several factors may explain this, such as these individuals may have higher levels of fatigue… a lower mobility and lower fitness levels. All of these factors can affect burning calories,” Karelis said.

There aren’t calorie breakdowns for specific sexual positions.

The good thing about Karelis’ research is that it provides a lot of information based on averages. The bad thing is that if you’re into specifics, it’s hard to narrow down energy spent on reverse cowgirl versus doggy style without a new trial.

Karelis said the study’s participants filled out a survey following each sex session, detailing their experiences along with the positions they used. Karelis noted that most participants used two or three different positions each time, so we know the data is representative of more than just a month of missionary sex. But unless you were to re-do the study with participants only having sex in one specific position, you can’t get a good sense of how different sex moves stack up against each other, calorie-wise.

Just because we don’t know how many calories you burn having sex standing up, let’s say, doesn’t mean we can’t discern other benefits from various positions. Hannah Davis, a Tennessee-based certified strength and conditioning specialist, said that such a position can work your inner thigh muscles if you’re the one being lifted, and could help your partner improve balance as well. And if you’re on top during missionary, you’re probably working your back extensor muscles, too. Silver linings all around.

Sorry, oral sex probably burns fewer calories.

There’s no good way to break this news, but because oral sex typically doesn’t require a ton of full-body aerobic activity, it’s likely not going to burn as many calories as intercourse.

“I don’t think [oral sex] plays a huge role in terms of an energy expenditure here,” Karelis added. “But again, this is actually a hypothesis and not something that’s been able to be documented.”

Sex shouldn’t replace exercise…

This should go without saying it, but we’re reiterating just in case: Sex is a great activity but it’s not a substitute for regular fitness. Karelis’ study compared participants’ calorie burn during sex to their energy expenditure after 30 minutes on a treadmill. No surprise ― sex won’t cut it as a replacement for your cardio routine.

According to his findings, “the energy expenditure during the 30-minute exercise session in men was 276 kCal or 9.2 kCal per minute, and in women 213 kCal or 7.1 kCal per minute” for the treadmill. (Again, sex burned around 101 for men and 69 for women.)

And definitely don’t try to use sex to lose weight. “You will have to expend huge amounts of energy with [sex] in order to start thinking about using that as a weight loss strategy,” Karelis said.

…But there are still plenty of other health benefits.

Even if you’ve got to stick to your gym routine, there are still tons of ways that sex is good for you. For example, sexual activity has been shown to increase cognition in older adults. It can also help you get a good night’s rest: Sex releases prolactin, a hormone that helps you fall asleep.

Getting busy can also help you work different muscle groups than you would at the gym. Davis said that during sex, women can engage their pelvic floor muscles, which she noted weaken over time or with childbirth and are crucial for bladder control.

And yes, there are ways to amp up your calorie burn during sex.

“Number one, make it last longer,” Davis said. The longer you’re aerobically active, the more calories you’re going to burn.

It’s also important to remember that burning calories during sex can be intensified if you’re actively thinking about it, Davis said. When you’re lying on your back, for example, you can choose to squeeze and engage your glutes. If you think about which muscles are working and make a choice to engage them further, you’ll get more out of a workout.

Davis added that another way to make your sex more aerobic is to add more positions into the mix. Switching from one move to another can get your heart rate up and can improve your flexibility too, she said.

Even if sex isn’t burning a marathon’s worth of calories, there are still plenty of reasons to get busy for your health.