Is Eating After Exercise Good or Bad?

Whether you're a serious athlete or health-conscious weekend warrior, getting the maximum benefit from working out is important. Do you wonder if intensive or light exercise after eating or before a meal provides the most gains to achieve your fitness goals? Sometimes, timing can make a difference.

Whether exercise after dinner is good or bad depends on the level of activity and intensity of your workout. Aerobic workouts, strength training or exercising for weight management may be most effective if done before eating. However, the timing of your meals for more casual exercise such as walking, may not be as critical to the overall benefits of your exercise routine.

The Academy of Nutrition and Dietetics says it's best not to eat immediately before an intense workout because digestion in your stomach is forced to compete with the demands of the energy required by your muscles. A session involving cardio after dinner may result in indigestion and GI discomfort while you train. And exercising strenuously on a full stomach can lead to cramps, upset stomach or vomiting.

If you are trying to lose some extra pounds, exercising before eating may have a greater fat-burning benefit. A review, published in the British Journal of Nutrition in October 2016, aimed to examine the metabolic effects of exercising on an empty stomach compared with eating breakfast beforehand. The meta-analysis concluded that aerobic exercise performed before eating a meal induced higher fat oxidation than exercising after eating.

Another study confirmed the benefits of waiting to eat until after your workout on increased fat burn and control of blood sugar. A six-week study in the Journal of Clinical Endocrinology & Metabolism, published October 2019, assessed the effects of exercise performed before versus after eating. Researchers determined that body fat utilization was about two-fold higher with exercise before versus after a meal, which also provided an increase in glucose insulin sensitivity.

Read more: What Type of Recovery Workout Is Best for You?

While there are benefits to working out on an empty stomach, it doesn't necessarily mean that it's always ideal. Working out while hungry may not be for you. If you don't eat you may feel sluggish or lightheaded and have reduced stamina. Hunger pangs and low blood sugar levels may prevent you from finishing your exercise routine.

If you prefer to eat something prior to your workout, concentrate on including high-carb foods that will give you the energy needed. But wait for the food to digest before exercising. Mayo Clinic advises waiting three to four hours after eating a large meal; if you eat a small meal or snack, wait one to three hours before working out.

Endurance athletes often choose to eat a meal containing low-glycemic index carbohydrates before exercise and find this may optimize their metabolism and maximize glycogen levels, according to a review published in May 2014 in the journal Nutrients. The study found that participants who consumed a carbohydrate-rich meal within 60 minutes prior to exercise actually achieved enhanced performance in some cases.

Read more: 10 Things You Should Never Do After a Workout

You need to eat the right foods and drink an adequate amount of fluid before and after exercising to help maintain blood glucose concentration, maximize exercise performance and improve recovery time.

Eat foods containing a combination of the protein and easily digestible carbs one to four hours pre-workout, suggests the Academy of Nutrition and Dietetics. Carbs are the fuel. Protein makes the right amino acids that your muscles need to function.

The American Heart Association (AHA) suggests some good choices for your pre-workout meal, which include:

• Whole-grain cereals with low-fat milk
• Whole-wheat toast
• Low-fat yogurt
• Whole grain pasta
• Oatmeal with fruit
• Brown rice
• Fruits and vegetables

You should eat only a small amount of unsaturated fat and limit your protein intake because these types of fuels digest slowly in your stomach and may inhibit the delivery of oxygen rich blood to your muscles, according to AHA.

If you have only five to 10 minutes before you exercise and need a quick pick-me-up, eat a piece of fruit, such as an apple or banana. And don't forget to hydrate. You can dilute 100 percent fruit juice with water to provide extra carbs with your fluid intake.

Consuming the right nutrients after you finish your exercise routine is critical for enhancing recovery and providing the macronutrients needed to rebuild and restore muscle tissue damaged from your workout. Preferably, you should eat within 60 minutes after your workout, says the Academy of Nutrition and Dietetics.

Read more: Why Post-Workout Nutrition Is So Important — and Exactly What to Eat

In addition to adequate fluids, your post-workout meal should consist of carbs and protein in the right proportions. Your body's glycogen stores are used as fuel during exercise so you should focus on consuming carbohydrates after your workout to help replenish them. You also need a small amount of protein to provide amino acids that help to reduce inflammation and build and repair your muscles.

The American Council on Exercise recommends a carbohydrate-to-protein ratio of 3:1. In other words, 3 grams of carbs for every gram of protein. ACE says this combination consumed within 30 minutes of exercise may nearly double insulin response, which results in more stored glycogen to be available for your next workout session.