Getting too much sugar in your diet may increase your risk for cavities and obesity, so the American Heart Association recommends trying to minimize the amount of sugar you add to your diet. But after some types of workouts, foods high in sugar, such as sports drinks, may be beneficial in moderation.
When Sugar Is Helpful
If you're participating in workouts lasting longer than 90 minutes, drinking a beverage containing carbohydrates, such as sugars, may help increase your endurance, especially if the drink has a mix of different types of sugars, according to the American College of Sports Medicine. The carbohydrates give your body more fuel to use during exercise, delaying fatigue. Once you finish exercising, even more carbohydrates may be necessary. Within half an hour of completing a strenuous workout, you should have a snack containing a mix of carbohydrates and lean protein, recommends the American Council on Exercise.
What Purpose It Serves
Carbohydrates, including sugars, get broken down during digestion to be used for fuel. When you have more fuel than you need immediately, a small portion of this fuel is stored in your muscles and liver in the form of glycogen, and the rest is stored as fat. Then, when your body needs extra fuel quickly, such as during a workout, it draws upon these glycogen stores, which need to be replenished regularly. This glycogen also helps regulate your blood sugar levels. Eating carbohydrate-rich foods after a workout helps to build up the levels of glycogen back to normal.
The Academy of Nutrition and Dietetics recommends getting between 0.5 and 0.7 gram of carbohydrates per pound of body weight after workouts of moderate to high intensity lasting more than 90 minutes. Most sports drinks contain 13 to 19 grams of carbohydrates in the form of sugars per 8-ounce serving. Berries, bananas, low-fat chocolate milk and whole-grain bread or oatmeal can all provide these carbs in a more nutritious way than drinking sugary water.
If your workout is short or isn't very strenuous, you probably didn't use enough glycogen to need sugar or other carbohydrates afterward. Workouts that don't increase your heart rate, don't cause you to sweat or don't leave you breathing hard at least part of the time also probably don't merit a post-workout snack. Eating a sugary or carbohydrate-rich snack after a light workout could mean eating more calories than you actually burned, making it more likely you'll gain weight instead of losing it.