You've probably heard the age-old advice that you shouldn't exercise for at least 30 minutes after eating. Although this doesn't give the full story, there is some truth to this statement. Digestion involves a complicated series of events that provide the necessary fuel and nutrients for proper body function.
While exercise after eating might seem like a good idea, it can actually hamper your workout due to the stomach upset you may experience.
Wait at least 30 minutes after eating a snack or small meal and several hours after a large meal to work out. Exercising too soon after eating can upset your digestive system.
How Digestion Works
Digestion begins in the mouth, where enzymes begin breaking down foods. The food will then move through your system to the stomach. The stomach prepares food for absorption by the intestines; it will not absorb most of the food you've eaten. Nutrient and water absorption occur primarily in the small and large intestines. Indigestible materials are then eliminated from the body. The entire digestive process typically lasts for 24 to 72 hours after eating.
Exercise After Eating?
The types of food you eat can influence how long digestion takes and what impact it has on your exercise. Generally, your body can easily digest simple carbohydrates like fruits. Part of the reason lies in their chemical structure. Digestion, after all, is basically a process of chemical reactions.
Proteins, on the other hand, are chemically more complex. These foods take longer to digest. Because they stay in your stomach longer, you may experience nausea from exercising too soon after eating high-protein foods.
Consider the Glycemic Index
In the gastrointestinal system, the pancreas and liver play vital roles in metabolism of the foods you eat. The pancreas helps to control your blood sugar. The glycemic index or GI measures how quickly sugar enters your bloodstream. The higher the GI, the more quickly this process occurs.
In terms of exercise, having sugar readily available will help fuel your muscles, particularly during intense exercise. During a high-intensity workout, the body first burns sugar for energy.
Wait It Out
According to HealthLine, wait at least 30 minutes after eating a snack or mini meal to exercise, and up to three to four hours after a larger meal. When you begin to work out, your body switches gears and goes into fight-or-flight mode. Digestion slows as your body directs blood flow to your muscles. Likewise, the body directs energy to the muscles.
The body has evolved so that digestion is a passive process, not the body's primary function during activity. If you wait to exercise, you can take advantage of the rise in blood sugar and the availability of energy for a more effective workout.
Eating During a Workout
Although exercise might increase your appetite, the body does not typically need additional food during a workout unless it lasts more than one hour. However, it is important to consume water before, during and after your workout to help prevent too much water loss through sweat.