Exercising on an Empty Stomach: Does It Burn Fat?

Are you an early morning exerciser with not enough time (or your forget) to have your pre-workout fuel?? Put it this way, “Do you set your alarm at 5:50 am for a workout class or routine that starts at 6 am?” This lack of time in between waking up and starting your workout does not allow you to give your body the right pre-workout nutrients. Therefore, you are basically “running on empty.”

Think about it…your last meal was most likely 8-10 hours before and your body has done a lot of work during your sleep of digesting and absorbing nutrients while your metabolism continues to burn. You wake up and your body wants you to “refuel it,” which simultaneously revs up your metabolism.

Many athletes and frequent (on infrequent) gym-goers push themselves to workout on empty stomachs with the belief that they’ll burn more fat.


IMG_1618The idea behind this is that exercising on an empty stomach forces the body to dip into fat stores for fuel (energy) instead of the quickly available carbohydrates (provided from the pre workout meal or snack). However, research shows that exercising this way is not beneficial and may even work against you.

The Strength and Conditioning Journal published a recent article that the body burns approximately the same amount of fat regardless of whether you eat before a workout. However, you’re likely to lose muscle when exercising in a depleted state because your body will dip into your protein stores (for energy). In addition, you’re likely to have a reduced exercise intensity and decreased total calorie burn.

The bottom line is that exercising on an empty stomach will NOT help you burn more fat (which is what you want). It will actually make you burn muscle (which is what you don’t want!).

So, start your morning off RIGHT with a nutritious and balanced breakfast! For example, before my 6 am morning workout at Sports Club LA or Sweat Garage, I will snack on ½ banana with almond butter and a few bites of cereal with nonfat plain Greek yogurt. (I don’t want to get too full before an intense cardio / weight routine). Then, I eat a larger well-balanced breakfast containing protein and whole grains or fresh fruit within 30 minutes post workout to aid in muscle recovery and replenish depleted glycogen (the stored form of glucose) stores!

To learn more about healthy breakfast ideas or pre-workout / post-workout meals and snacks, schedule an appointment with Courtney Walberg, Registered Dietitian, Certified Personal Trainer and Founder of Nutrition For Body And Mind.