Is It OK to Run on an Empty Stomach?

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"I usually run in the morning and I don't like eat before my runs. Can I run on an empty stomach?"

Eating Before a Run or Running on Empty

Ideally, you want to try to eat something about 90 minutes to 2 hours before running, so you have time to digest your food, you're fueled for your run, and you're not starving during your run. But that obviously doesn't work for everyone. If you're running for under an hour, you can get away with not eating before.

If you have been running on an empty stomach and haven't had any ill effects such as being light-headed, dizzy, low on energy or overly fatigued, you can probably continue to do it that way. However, it's smart to bring along sports drink or an energy bar as a rescue snack in case you find yourself suddenly woozy or worn out. If you haven't been running on empty but are tempted to start doing it, bring along sports drink and/or a snack.

The answer will be different, of course, if you have a condition such as diabetes, in which case you need to discuss this with your doctor and find a good solution for your morning runs.

Hydrate Before Your Run

But definitely make sure you're hydrating before you start. You'll be dehydrated because you haven't had anything to drink for however long you've been sleeping. Drink at least 8 ounces of water when you first wake up. You could drink a sports drink before your run so you know you're at least getting some calories.

You should also drink water during your run if you're running longer than 30 minutes.

Fuel Up Before a Longer Run

If you're running longer than an hour or doing a really intense speed workout, it's best to force yourself to wake an hour and a half early or more (you could always go back to sleep!) for a small meal.

If you don't eat anything, you'll burn through your stored energy and start feeling fatigued and possibly hungry during your run.

Eating a 300-500 calorie breakfast of mostly carbs will ensure you're not running on fumes. Some examples of good pre-workout fuel include: a banana and an energy bar; a bagel with peanut butter; or a bowl of cold cereal with a cup of milk. If you're eating less than an hour before your run, aim for a light, 200-300 calorie snack such as toast with peanut butter or a cup of yogurt.

Some people can get away with not eating at all before a run of any distance, but you'll run stronger if you eat something before. If you're doing a long run and you really don't have time or your stomach gets upset if you eat before running, try eating something small, such as an energy gel, about 30 minutes into your run.

Also see:


Kirwan J, O'Gorman D, Evans W. A moderate glycemic meal before endurance exercise can enhance performance. 1998. J Appl Physiol 84: 53-59.

American Council on Exercise. ACE Personal Trainer Manual, 3rd Edition. San Diego: American Council on Exercise, 2003.

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