Working Out on an Empty Stomach May Help Burn More Fat

Many people are unsure if they should eat before exercising or if they should fast. A recent study suggests that the answer is fasting, if you want to burn more fat.

Participants in the study included ten healthy but overweight men. For the first test, all of the men walked for 60 minutes at 60% maximum oxygen consumption on an empty stomach. For the second test, they performed the same walk two hours after consuming a high-calorie, carbohydrate-rich breakfast. The researchers took blood samples after eating or fasting and also after exercising. They also collected adipose tissue samples both immediately before and one hour after walking.

At the conclusion of the study, the researchers noted that the expression of the genes PDK4 and HSL increased when the men fasted and exercised. In comparison, the genes decreased when they ate and then exercised. This likely indicates that the men’s bodies were using stored fat for metabolism when they exercised on an empty stomach, versus using the carbohydrates they consumed when they exercised after eating.

Researchers from the University of Bath in the UK conducted the study. It was published on March 14, 2017, in the American Journal of Physiology.

Regular exercise is one of the best things you can do for your health. Previous clinical studies suggest that even moderate exercise may help with blood sugar control, reduce body weight, improve heart health, improve respiratory health and reduce the risk of dying prematurely.