Q: Does working out on an empty stomach help to burn more fat? – Lindsay; Evergreen, CO

A: That’s a great question.  You bring up a myth that’s in dire need of busting.  Contrary to the mis-information doled out by many an arm-chair fitness expert, working out on an empty stomach does NOT cause your body to fuel exercise by burning stores of fat.  In fact, that theory was soundly refuted in a study by the Strength and Conditioning Journal which found that working out on an empty stomach generally leads the body to burn calories from muscle instead.  Now, if you’re thinking that’s not so bad, given that muscle weighs more than fat – wrong again!  All that time you spend working out in the gym is to gain muscle, because muscle tissue is metabolically active, helping you burn calories.  So the last thing you want to do is burn muscle tissue.

The other side effects of working out on an empty stomach are low energy and low blood sugar.  It’s like getting in your car to drive across town with your gas tank nearly empty.  You won’t get very far before your car stalls out completely.  So, no fuel and no energy – think you’ll burn many calories?  Not likely.  Your best bet is to eat a healthy, light meal or snack prior to working out.  Not only will you feel more energetic, but your body will burn more calories, and you’ll feel less hungry, both of which will result in keeping your weight in check.

Next question — should you eat a meal or just a snack?  Eating before a workout is all about the timing.  If you opt for a full meal, you need to eat 1-2 hours before your workout. For me, snacks work best, since the size of the meal should be about half the calories the workout will burn – typically 100-200 calories 30 minutes before my session. I try to choose fast digesting carbohydrates (which are high on the glycemic index) and avoid fatty foods. No one knows your body better than you; some people simply cannot eat before a workout. But knowing the science behind sports nutrition might help you to make an informed decision about working out on an empty stomach. Either way, keep in mind that when you’re moving, you’re improving!

Smart Choices for Fueling Workouts

Fruit juice or fruit smoothie

Yogurt or yogurt smoothie

Fruits – banana, watermelon, pineapple, mango, apricots

Sports drinks

Energy bars with 3-5 grams of protein and 15 carbs

Pretzels

Bagels, but not whole grain

Hard-boiled egg or egg whites

Hummus and raw veggies

Oatmeal

Nuts, trail mix, dried fruit

Cottage cheese with fruit

Cereals with at least 3 grams of fiber

Whole grain Fig Newtons

Milk (white or chocolate)

1/2 whole grain sandwich with almond or peanut butter, turkey or chicken