IF you’ve never heard of the workout trend “fasted cardio,” now is the time to find out. Put simply, it refers to exercising on an empty stomach, which usually means getting in your sweat session before you eat your breakfast. Many fitness enthusiasts swear by the practice, including Jennifer Lopez.

Though past studies seem divided on the benefits of performing cardio in a fasted state, a study published in the Journal of Clinical Endocrinology & Metabolism found that participants who performed cardio before eating their first meal of the day actually doubled their fat burn compared to those who exercised with food in their belly.

Rates of whole-body lipid utilization, which means “fat burn,” were around twofold higher with exercise before versus after carbohydrate provision, and this difference between the conditions was sustained throughout the whole six-week intervention, observes the study.

The research, conducted at the University of Bath in the U.K., focused on a group of sedentary but healthy men and divided them into two groups. One lived normally, while the other worked out in the mornings using stationary bikes and wearing fitness trackers.

Those who exercised were either given shake before their ride or simply water that was disguised as a shake. At the end of the six-week study, as mentioned, those who didn’t have the shake burned away double the calories.

The researchers say that the enhanced fat burn is because the fasted state forces the our bodies to burn stored energy in their muscles and fat.

However, there are some caveats here. Remember that “fat burn” doesn’t necessarily translate directly into “weight loss,” and when your body shifts to alternative fuel sources when no others are available, it may not always turn to just your fat.

“Research shows that there’s an increase in muscle breakdown when we exercise fasted, so it could actually decrease our strength,” Meghann Featherstun, a specialist in sports dietetics, explains.

So if you’re someone who is looking to build muscle, it’s better to train with some fresh energy stores waiting in your belly.

If you train super hard, you’d be wise fuel up. “In a fasted state, the physiology doesn’t typically have the optimal resources for this type of hardcore exercise,” says David Chesworth, a personal trainer.

(SD-Agencies)