Are you surprised by this?

While calorie counting isn't everything, it is a handy way to keep track of how effective an exercise is. With all the boring and difficult exercises around, it was always a delighted to know that at least having fun in the bedroom counts towards getting fit. So if you didn't manage to get to the gym, you could always tell yourself you at least burned a few calories getting intimate with your partner. However, it seems that it's not quite as effective as we thought. A study in the New England Journal of Medicine looked at this, and made an estimate based on an average man. So, a man in his mid-to-early 30's engaging in the average length of sexual activity – that’s six minutes apparently– would burn off 21 calories. 21 measly calories. This is based on an estimate of a person's rate of energy conversion among other factors. So while it's really just an educated guess, it's also a bit of a disappointment. If you feel that 6 minutes doesn't sound right, or put a lot of energy in in the bedroom, you can check out this fun, sex calculator which lets you enter a number of factors such as gender, body type, position, pace and length of time, which you may feel gives a better average. Here's an example below.