Should You Run Before or After Eating?
To eat or not to eat—before or after running—that is the question. Few topics have been covered so extensively by running publications and there are plenty of scientific articles supporting both. Bottom line: your decision to follow either can't be based on "other people's experiences"; it's your choice to make.
Would it surprise you to learn that our bodies respond to pre- and post-race eating in distinct ways? This topic is particularly important if you factor in marathon days or if you have a condition that mandates one or the other.
When in doubt, consult your body. Whether you turn out to be a runner who's able to train after eating or experience shows that the less you eat before you run, the better your performance, you'll find answers courtesy of learned minds we've consulted on a topic that's literally food for thought!
What feels right to you?
It's the ideal question to ask when attacking this subject because if you experience any sort of distress when you run after eating, you can skip the rest of this article! Assuming you don't have a problem eating before you run, the amount of food you ingest could be a deal breaker.
Mayo Clinic researchers insist that the choice to eat before or after a run is unique to every individual because everyone's digestive process is distinct. It takes anywhere from 6 to 8 hours to get the same mix of food through different stomachs and small intestines, so it behooves you to figure out your own gastro-intestinal (GI) timeline.
Your physiology may force you to eat before your run because you find that you become lightheaded, sluggish and ill if you run on an empty stomach and have no energy stores remaining in your system from your last meal. Alternately, chronic disease like diabetes may leave you with no choice if you don't want your blood sugar to plummet.
Does size matter?
When it comes to pre-run meals, you bet! If you've tried to consume a large quantity of food before running, that's a great way to sabotage your experience. But some foods are worse than others, even in small amounts. Chow down on dairy, refined grains, high-fat foods, too much caffeine, sugar-laden treats and high-fiber foods before running and the results won't be pretty.
Eliminate foods in those categories, keep portions small and don't run immediately after you put down your fork, spoon or toast to get the nutritional boost you need to start your morning, afternoon or evening run.
No time to start preparing anything that requires more than a knife or a toaster? Make up your own pre-run meals and you improve your chances of avoiding gastric distress.
Were you diagnosed with a GI-related illness?
If you suffer from a chronic gastric disorder—diarrhea, constipation, gastroenteritis, colitis and irritable bowel disorders-you already battle demons that impact a run more than most. Lots of runners change their diet to manage their condition, but the digestive tract may still react as stomach contents are jostled during a run, blood is diverted to muscle, fluids shift or dehydration threatens.
On the other hand, there are precautions you can take that short-circuit crises, so if you know you're at risk, sports doctors and coaches recommend keeping a diary to track your body's running behavior both before and after eating. Check out medications for active people battling GI disorders, too.
Timing is everything
Having determined yourself to be the person who requires sustenance before running, the length of your run may help you decide just how much you'll eat. You need energy. But you'd prefer to skip cramps and nausea, so base your downtime between eating and running based on the intensity of your run.
If you run for an hour and push your limits, an hour's rest between a viable snack and your first footfall is suggested. On the other hand, we suggests extending that time to between 1.5 and 2 hours. And don't discount the power of the energy gel when there's no time make toast or find a banana.
Pros and cons of running before eating
- You don't feel "weighed down" if you run on an empty stomach.
- Blood flow goes to muscles, not the digestive system.
- You burn more fat on an empty stomach while running than you do after eating.
- Hunger could ruin your run and make you grouchy and irritable.
- Running on an empty stomach could trigger muscle breakdown.
- It's possible to experience side effects like feeling faint or even becoming disoriented.
Pros and Cons of running after eating
- You build more muscle with a snack under your belt.
- Eating before running restores the body's glycogen faster.
- You can run further thanks to the caloric boost you get from food.
- For some runners, even small snacks trigger stomach upsets.
- You could feel bloated, experience "sloshing" or cramps if you eat first.
- Even beneficial fiber may cause distress, says University of Adelaide Exercise and Sports Science lecturer David Bentley.
What's your secret to running before or after you eat? Is it a specific snack or have you found a way to run on an empty stomach that you would like to share?