Should You Exercise on an Empty Stomach?

Question: Should You Exercise on an Empty Stomach?

If I exercise on an empty stomach in the morning, will I burn more fat?

Answer: The theory behind this is that your blood sugar levels are low when you're in a fasted state (after going all night without eating) which targets more fat burning.

The problem is that some studies have shown that fat burning doesn't really start until you're 20 minutes into your cardio workout. That means you've wasted 20 minutes without a good source of fuel to sustain you. That could lead to fatigue before your body even starts metabolizing fat, which might mean shorter (and/or crappier) workouts in which you burn less calories than if you'd eaten a small snack to keep you going you. Critics also say you may even burn muscle if you don't have the necessary fuel for your workouts.

There are some other benefits to eating before your workout:

• It can boost recovery and strength gains
• It can help you sustain longer, more intense workouts
• It can help you avoid low blood sugar, which can make you feel dizzy or nauseous
• It can make your workouts more enjoyable (since you're not thinking about eating the whole time)

The bottom line is, it's up to you and the type of workout you're doing. Some people are fine doing cardio without a meal in the morning, although they find they may need more fuel for a strength training workout. Other people workout so early, they may not have time to eat anything. The best answer to this is to do what works for you. Don't go hungry just because you think you're burning more fat...after all, if you cut it short or lower the intensity because of low energy, how much fat are you burning anyway?

If you do eat before a workout, make sure you give your body time to digest. The larger the meal, the more time you'll need. But, if you choose a light snack (100-200 calories) and stick with higher carb fare, you can probably exercise after about 30-60 minutes. Try some of these pre-workout snacks to get your body ready for exercise:

• Banana (or other type of fruit)
• Yogurt
• Oatmeal
• Energy bar or gel
• Fruit smoothie
• Sports drink

Updated 12/7/2005