What’s the best time of day to exercise is a debate that will run and run – though realistically the answer is probably the time that suits your lifestyle. But if you’re after body-shaping results the latest evidence suggests an early workout may be better than exercising later, especially if you’re trying to burn fat.
Health experts at Bath and Birmingham universities collaborated on a study that’s been published in the Journal of Clinical Endocrinology and Metabolism. It found people who exercised before breakfast burned double the amount of fat than those who exercised later. That’s right, double the amount of fat. And it’s all to do with controlling blood sugar, apparently.
The study involved 30 overweight or obese men working out before breakfast, after breakfast or not working out at all for six weeks. The researchers say that the early morning exercisers burned more fat because their insulin levels were lower while they were exercising – a consequence of not having had anything to eat. And this, they think, meant the early exercisers used more of the fat from their fat tissue and muscle-stored fat than the men who ate first and exercised later.
Unfortunately, over the course of six weeks this didn’t lead to any differences where weight loss was concerned. But according to the researchers it did have a significant effect on the before-breakfast exercisers’ health. That’s because while keeping their blood sugar levels under control the participants were potentially lowering their risk for diabetes and heart disease.
Timing is key
“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,” says Bath University’s Dr Javier Gonzalez. “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’s co-author, Birmingham University’s Dr Gareth Wallis, adds: “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.”
If you’re not a morning person, chances are this news won’t make you jump out of bed and straight onto the treadmill. But it may be worth giving the idea of delaying your breakfast until you’ve done some exercise some thought.