How much you exercise is important, but new research says how you time your exercise is too. The study looked at the relationship between mealtimes and when you work out.
Exercising before and after a meal
Researchers from the University of Bath recruited 30 men who were overweight or obese to determine if exercising before or after a meal was more effective. They split the men into three groups:
Group 1 exercised and then ate breakfast.
Group 2 ate breakfast and then exercised.
Group 3 made no changes to their lifestyle.
After 6 weeks, the scientists found that Group 1 burned twice as much fat as those who exercised after eating the identical meal. Why? Because your body has been fasting while you sleep, lowering your insulin levels during exercise. This allows your body to use up more fat for energy.
In addition, the men in Group 1 proved to be better at controlling their blood sugar levels than the other two groups.
“Importantly, while this didn’t have any effect on weight loss, it did dramatically improve their overall health,” says Dr. Javier Gonzalez from the University of Bath’s Department for Health. “[This effect is] all the more remarkable, given that both exercise groups lost a similar amount of weight and both gained a similar amount of fitness.”
It’s also interesting to note that the men in Group 1 were no better off in terms of insulin response after they ate breakfast than the control group.
Caveats to the study
More studies—and longer ones—will need to be done to see if the results can be replicated. It’s worth pointing out that because this study was only done on men, it could produce different results if the participants were women. In addition, the breakfast used for the study was high in carbs, so another study would need to determine if a low-carb breakfast would produce the same results.
