“In their own research, Melanson and his team studied moderately active people who, on separate days, performed low-intensity or high-intensity cycling, or no structured exercise at all. They repeated their experiment with endurance athletes (competitive runners and triathletes), while comparing sedentary obese people with sedentary lean people, and then again while comparing older men with younger men.

None of these studies, which involved a total of 65 exercisers whose dietary intake was closely controlled, showed that people burned substantially more fat in the 24 hours after they exercised than on days when they didn’t exercise. Melanson says other experts in his field have been “flabbergasted” by the results.”