How many calories are burned during exercise?

If moderately/very active how many more calories do you burn than a sedentary person? If you have been drinking Doubly Labelled Water (DLW, see below), not nearly as many as you might think...


You go for a long walk, or cycle over the hills on the bike, or do a session at the gym. Then later, a cake with your coffee, thinking it’s okay, your fit gadget said you expended four or five-hundred calories? Think again.


Studies show that daily calorie expenditure of sedentary, moderately active and intensely active people are not that different. An article in February 2017 Scientific American magazine by anthropologist Herman Pontzer lays out his Doubly Labelled Water experiments, and references other studies, to explain that from couch potato to moderately active, there is a difference daily of about 200 calories, plateauing from moderate to intense activity.


Scientists looked at hunter-gatherer and farmer communities in Tanzania, Guatemala, the Gambia and Bolivia, and found, all things considered, that they expend much the same calories as adults in the Western world.


Others found the same when they compared animals in the wild to those in zoos or labs.


How can that be? We’ve been led to believe that the more activity we do the more calories we use. Pontzer himself was surprised to find otherwise. He, and others, suspect that metabolic adaptations are made as our activity levels increase, and they help keep us healthy. The more activity we do, the more resources are re-directed within the body. For example, energy may be diverted away from the inflammation response, which if “overfed” for years is linked to cardiovascular disease and autoimmune disorders.


Exercise alone is very unlikely to fix a weight problem but it can supply a long list of benefits. The combination of exercise and calorie control is the most successful strategy for weight management. 


The body is very adaptive. It has evolved to go through times of feast and famine. The late 20th century and 21st century has been a time of feast, an era of over-consumption and food waste. But it’s not necessarily been a time of unrestrained gluttony. People do not become overweight overnight. Those that have, trundled along through the years, moving through waist sizes gradually. A person could eat a good balanced diet, all the right macros, the proper nutritional quantities. But it doesn’t take much to overdo it. Try the link below and use the calculator.  See what a biscuit or bag of crisps per day can do over twelve months.


Even a very small amount can become excess. We should think long term about what we do. Short-term decision making is not helped when the phone app says you've used 500 calories in an hour session. That helps only in confusing us about what is really happening in our bodies. 


(DLW - The Doubly Labelled Water technique is likely the best method for measuring calorie expenditure. DLW is “water” but uses different isotopes of hydrogen and oxygen. You drink the stuff then pee then send it off for analysis. The proportion of isotopes is dependent on H20 and CO2 output, which accords with energy burned. Simple, eh? )