What are the Benefits of Exercising on an Empty Stomach?
It’s an ongoing debate within the world of fitness: should you eat breakfast before exercising in the morning, and are there any benefits to working out on an empty stomach?
Like with most questions about exercise, the all-encompassing answer to this question is that it depends.
“It all depends on what type of training you are going to do and for what purpose,” says John Rowley, Wellness Director for the International Sports Science Association (ISSA). What may be an advantage for one person could be a disadvantage for another.
The main advantage to exercising on an empty stomach: the potential to burn more fat. “Your muscles don’t have much sugar to draw from so you are more likely to tap into your stored energy, which means releasing and burning what I refer to as surplus fat,” says Founder and CEO of Diet Free Life, LLC, Robert Ferguson, M.S., C.N.
In that case, exercisers with weight loss goals might find a slight advantage in waking up and exercising first thing in the morning before eating breakfast or fasting for a few hours before a mid-day or evening workout.
“The less glucose you have in your system the more fat you will burn,” says Rowley.
However, if your goals are performance related (e.g. to improve strength or speed), working out without fueling up probably isn’t your best bet because a lack of available energy might prevent you from putting forth your best effort.
“I would expect a person wanting to improve their physical fitness to fall short of exercise performance for the sole reason of not being fueled to optimize their training session,” says Ferguson.
Rowley adds that in a case like this you’ll want more fuel for your training.
Ferguson also notes that if you’re diabetic or frequently experience low blood sugar it’s best to eat breakfast or a small snack prior to your workouts, especially if you’re exercising in the morning just after waking up.
No matter if you started on an empty stomach or snagged a snack before your workout, both experts advised about the importance of refueling afterwards.
“When you exercise you experience a hormonal boost and as a result, you want to replenish with food and get plenty of rest to optimize your recovery,” says Ferguson. “The higher the intensity, the more you want to lean toward consuming what I refer to as fast carbs like rice, pasta and potatoes.”
If you’re goals involve building muscle and most of your workouts are comprised of strength training, Rowley recommends eating at least 45 minutes after exercising. “This is also an anabolic window, so all this fuel will go towards glycogen replacement and recovery,” he says.