Does Exercising Before You Eat Breakfast Really Help Your Health? – Runner’s World

• According to a new study published in the Journal of Clinical Endocrinology & Metabolism, working out before eating breakfast can help you burn fat and respond to insulin better.
• However, it’s important to note that doing what works best with your personality, lifestyle, and schedule is key. In other words, don’t force yourself to exercise before breakfast if you truly can’t—working out at any point of the day is better than not working out at all.

It seems that people generally tend to fall into one of two camps: those who head out the door for their morning run without eating anything and those who need something in their stomachs first. But is one more beneficial to your health than the other? It’s a possibility, according to new research out of England.

In the six-week study, published in the Journal of Clinical Endocrinology & Metabolism, 30 overweight, inactive men were split into three groups:

1. No exercise at all
2. Ate a carb-only breakfast before exercise
3. Ate a carb-only breakfast after exercise

Those in the exercise groups cycled at a moderate intensity three times per week at 50 percent of their peak power output during weeks 1 through 3, and at 55 percent of their peak power output during weeks 4 through 6. During week 1, participants cycled for 30 minutes; during week 2, participants cycled for 40 minutes; and during weeks 3 through 6, participants cycled for 50 minutes.

Participants consuming a carb-only breakfast (either two hours before or after working out) were given a drink that contained 1.3 grams of carbs per kilogram of body mass with vanilla flavoring that was a 20 percent carb solution. Participants who didn’t exercise at all throughout the study were given the same carb-rich drinks three days a week for breakfast and a placebo to drink with their lunch.

The researchers found that those who exercised before breakfast burned two times the amount of fat than those who exercised after breakfast. They also responded better to insulin—“all the more remarkable given that both exercise groups lost a similar amount of weight and both gained a similar amount of fitness,” Javier Gonzalez, Ph.D., study author and lecturer of human and applied physiology at the University of Bath, said in a press release.

One possible reason why exercising before breakfast leads to greater fat burn, according to Gonzalez, is due to availability of fatty acids—which, among other functions, fuel your cells if glucose isn’t available.

“When we exercise, we increase the number of fatty acids that the muscle is exposed to, and when the muscle sees these, it causes a cascade of signals that lead to [muscle] adaptation,” Gonzalez told Runner’s World. “By exercising in the overnight fasted state, we increase the amount of fatty acids that the muscle is exposed to.”

And that can lead to greater health benefits: By burning more fat within your muscles, your muscles will adapt more to the exercise, Gonzalez said. That’s important because the more your muscles adapt, the stronger they’ll get.

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Gonzalez and his colleagues also saw the muscles produce more of a key protein that helps take sugar out of the bloodstream, leading to lower insulin levels, which contributes to improving health, he said.

“High levels of insulin are linked to the development of type 2 diabetes and cardiovascular disease, so a lower insulin level is thought to reduce future risk of these diseases,” Gonzalez said.

Still, there are some limitations of the study to take into consideration. For one, this study was only in men with who were overweight or obese, so it’s not entirely clear whether the same results would be seen in women, or in those who are a normal weight. More research needs to be done on those populations before a firm conclusion can be reached.

Plus, even if you are trying to exercise to shed some extra pounds or improve your health, you shouldn’t look to early, prebreakfast workouts as the definitive answer. The results aren’t enough that you absolutely have to force yourself to wake up early and get your runs or workouts in before breakfast if you don’t have time to do so, or simply aren’t a morning person.

Exercising at another time of day is better than not exercising at all, according to Gonzalez. While the results of this study could help those struggling to lose weight, everyone is different, and ultimately, you have to do what’s best for you personally.

Associate Health & Fitness Editor Danielle specializes in interpreting and reporting the latest health research and also writes and edits in-depth service pieces about fitness, training, and nutrition.