Found on RunnersWorld.com and written by Susan Paul
I’ve read articles that say you shouldn’t eat a large meal (more than 200-300 calories) before a run. They never seem to mention how long you should wait to run if you do have a large meal. What’s the best timing on eating before running?
– Pete Kaszyk
Good point! Let’s define “large meal” as a meal containing more than 600 calories with several ounces of protein or meat, carbohydrates, vegetables, and dessert—a typical dinner or large lunch. If you have a meal like this, you should wait three to four hours before running. Why? Because after a large meal, the body must digest this food.
Digestion requires a rather large amount of the body’s energy. To facilitate the digestion process, the body directs more blood flow to the stomach and other internal organs to accomplish this work—which is also the reason we often feel sleepy following a large meal. The increased blood flow to internal organs means less blood flow is available to our large muscle groups, like our legs and arms. When we exercise, the opposite occurs; blood flow is redirected from internal organs to the large working muscles to provide the necessary energy for muscle contraction.
When we have a large amount of food in our stomach, running is difficult or uncomfortable because our body is simply not designed to do both digestion and exercise at the same time. Stomach cramps, stomach aches, or gastro-intestinal distress are the most common complaints when trying to run on a full stomach. The mechanical mixing and jostling that naturally occurs while running can upset the digestive tract too.
Now that said, some athletes are able to eat and run. Endurance athletes train their bodies to eat on the run. Even at the marathon distance, runners must ingest some nutrition during the race, although hardly a large meal. Experimenting in your training with eating and running will let you know just how much you are able to eat before a run.
For the best training results though, allow three to four hours after eating before running, especially if the workout calls for some intensity.
All the best,
Susan Paul, MS
Susan Paul has coached more than 2,000 runners and is an exercise physiologist and program director for the Orlando Track Shack Foundation. For more information, visit www.trackshack.com.
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