Exercising before breakfast can double the amount of fat burned, research finds.
Levels of insulin in the body are much lower before breakfast, so the body uses more fat from the body to help generate fuel for exercise.
Doubling fat burning can also dramatically improve overall health.
The muscles of people exercising before breakfast had higher levels of key proteins that transport glucose.
Dr Javier Gonzalez, study co-author, said:
“Our results suggest that changing the timing of when you eat in relation to when you exercise can bring about profound and positive changes to your overall health.
We found that the men in the study who exercised before breakfast burned double the amount of fat than the group who exercised after.
Importantly, whilst this didn’t have any effect on weight loss, it did dramatically improve their overall health.
The group who exercised before breakfast increased their ability to respond to insulin, which is all the more remarkable given that both exercise groups lost a similar amount of weight and both gained a similar amount of fitness.
The only difference was the timing of the food intake.”
The study included 30 overweight and obese men who were put into two groups.
One group exercised before breakfast and the other one afterwards.
The increased fat burning is down to the lower insulin levels before breakfast.
Although exercising before breakfast did not lead to more weight loss, the study was only six weeks long.
However, exercising before breakfast was linked to other health benefits, including a stronger ability to respond to insulin.
This is linked to lower risk of heart disease and diabetes.
Dr Gareth Wallis, study co-author, said:
“This work suggests that performing exercise in the overnight-fasted state can increase the health benefits of exercise for individuals, without changing the intensity, duration or perception of their effort.
We now need to explore the longer-term effects of this type of exercise and whether women benefit in the same way as men.”
The study was published in the journal The Journal of Clinical Endocrinology & Metabolism (Edinburgh et al., 2019).