Working out before eating breakfast burns about 3 grams more fat than working out after eating, because your body has to use stored fat for energy when you haven’t eaten.

When you work out in the evening without eating beforehand, your body burns more fat and less sugar for energy during the workout.

Whether you're fit or out of shape, male or female, young or older, working out before breakfast still burns more fat than after eating — as long as you're not sprinting at max effort.

Working out on an empty stomach in the evening makes your body burn more fat and less sugar during the workout.

Doing a tough weight workout before jogging or cycling helps your body burn more fat while you're doing the cardio.

Whether you exercise before or after eating, the amount of fat floating in your blood doesn’t change much during the workout — so the extra fat burning when fasting must be happening inside the muscles, not from more fat being released.