Kate Hudson considers sex a workout. Here's how many calories you actually burn during the act.

• Kate Hudson posted a video on Instagram saying she counts sex towards her WW daily workout points.
• Previous research suggests the act can burn calories, but how many depends on what you're doing.
• Sex can have other health benefits like stress reduction and lowered blood pressure.

Kate Hudson told her 13.4 million Instagram followers she counts sex towards her daily workout goal.

"Hey, guys. I've got some really interesting news that I'm very excited about right now," Hudson said in the video published June 10 to promote WW's new app.

The actress said that an average hour-and-20-minute sex session with her partner, Danny Fujika, is worth six WW (formerly known as Weight Watchers) points

A post shared by Kate Hudson (@katehudson)

"If anyone needs me, I'm going to be in my bedroom for a good, I'm going to say, hour-twenty," Hudson said. "If he can handle it."

Though it could be considered an unconventional way of working out, Hudson may be right. Previous research suggests working out burns calories.

The number of calories burned during sex varies depending on what you're doing

A 2013 study by researchers at the University of Quebec in Montreal found on average heterosexual men burn 101 calories during sex and women burn 69.1 during an average sex session. Researchers also concluded men burn an average of 4.2 calories a minute during sex and women burn 3.1 calories a minute.

Another study published in 2013 in the New England Journal of Medicine found men burn an average of 21 calories during six minutes of sex. Insider also previously reported people on top tend to get the best workout.

While the exact number of calories burned during sex depends on many factors, researchers agree it does expend some energy.

In addition to burning calories, sex can have a number of positive health benefits including stress reduction, an increase in libido, and lowered blood pressure.