The gym bunny’s equation is simple enough: calories in versus calories out. After you’ve worked up a sweat in the gym, you should have gained the licence to treat yourself to a snack afterwards.
In practice, the maths is difficult to get right: it’s all too easy to overestimate how much we’ve burnt in a session, and underestimate the calories in a snack. The depressing result is that many people (up to 68%, in one study) hoping to shed pounds actually put on weight during their exercise regime.
Fortunately, BBC Future has scoured Harvard Medical School’s comprehensive table of the calories burned during everything from sex to long-distance cycling. Using this information, we equated exactly what it would take to burn off your favourite snacks. (The exact figures will vary from person to person – all the data here assumes an 11-stone, or 70kg, frame.)
You may be surprised by just how little you burn during seemingly energetic activities, such as sex
Compared to sleeping (which itself burns some calories), even something as simple as sitting at a computer, chewing gum or reading a book is equivalent to eating some modest nibbles. You may be surprised, however, by just how little you have earned during seemingly energetic everyday activities, such as sex – or how far you have to travel before you have burnt off a burger and chips. Exercise offers many benefits besides weight loss, of course. But if you are aspiring to a trimmer, more toned figure (or simply want to remain a stable weight), it’s worth knowing the facts before you hit the gym or raid the pantry.
David Robson is BBC Future’s feature writer. He is @d_a_robson on Twitter.
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