Diet and Nutrition

Scale stuck? Rethink eating before and after exercise

Diet and Nutrition

Our registered dietitian, Susan Rodder, is an avid bicyclist who understands the importance of nutrition and hydration during exercise.
“I exercise often, but I still can’t seem to lose weight.”

This is a common hang-up I hear from people of all fitness levels – you’re keeping up with your workouts, but the scale just won’t budge. So what’s the deal?

The way you eat may be keeping you from reaching your health and fitness goals. Exercise can make you feel hungry, and it’s easy to misjudge how many calories you really need to consume before, during, and after exercise.

The amount you should eat to fuel or refuel your body is based on the amount of time you’ll be exercising and the activity you’re planning to do. For example, if you’re going for a 3-mile run at a pace of 10 minutes per mile, you’re going to burn around 300 calories. Walking the same distance will burn fewer calories, and biking will fall somewhere in the middle.

You should also be mindful of what you drink – sports drinks can help support you if you sweat a lot or if you exercise for a long period of time, but they can also pack a lot of calories you may not need for shorter, less intense workouts.

What should you eat before exercise?

I usually recommend eating a carbohydrate-rich snack 30 to 60 minutes before exercising. Fueling up will supply glucose to power your soon-to-be-active muscles. If you eat too much before your workout, you will feel sluggish and may even have to make an emergency restroom break.

Some easy-to-digest snacks that won’t “cancel out” the calories you’re about to burn during your workout include:

  • Peanut or almond butter on whole-wheat crackers
  • Fruit
  • Yogurt
  • A granola bar (if under 300 calories)

It’s also important to stay hydrated. If you know you’re going to work out, make a conscious effort to keep up with your water, especially in the hour before a workout. Avoid drinks that contain a lot of caffeine – such as energy drinks – before and during exercise. Caffeine is a mild diuretic and can increase your risk of dehydration.

Do you need to eat during exercise?

There are a lot of gimmicky foods – like protein bars and drink mixes – that you may be tempted to eat during exercise. Usually they’re not necessary. They can give you a sour stomach and negate the calories you’re burning.

That said, if you’re exercising for more than two hours – like taking a long hike or running a half marathon – you should eat easy-to-digest carbohydrates mid-workout to help maintain your energy.

Try these options:

  • Banana
  • Bread with honey or jelly
  • Sports gels or gummy chews
  • Dry cereal
  • Bite-size pieces of a granola bar (a bar with more oats and dried fruit than nuts)

I also recommend drinking water during exercise to avoid dehydration. Water is enough to keep you hydrated when you’re exercising 60 minutes or less at a low or moderate intensity level. You may lose more sodium through sweat than you realize, so it’s important to sip fluids even if you don’t feel particularly thirsty.

If you sweat a lot or are working out under the hot Texas sun, you may want to drink a sports drink to rehydrate and replenish lost electrolytes. Look for one that contains around 15 grams of total carbohydrate, 100 milligrams of sodium, and 30 milligrams of potassium per 8-ounce serving.

You also may want to try eating salty foods to replace the sodium lost through sweat. Pickles or pretzels work well, or you can add salt to diluted juice. Here is the recipe if you want to try it:

  • 3 ½ cups water
  • ¼ to ½ cup 100 percent fruit juice
  • 2 to 3 tablespoons of sugar or honey
  • ¼ teaspoon of table salt

How should you refuel after exercise?

Exercise can make you hungry – but it’s easy to eat more calories than you need. If you’re exercising at a low to moderate intensity level for 60 minutes or less, you probably don’t need to eat anything extra after your workout. Waiting until your next meal is usually fine.

But if you follow a dedicated exercise routine to build muscle mass – like resistance training or weight lifting – eat up to 20 grams of lean protein within 60 minutes after exercising. Protein can help repair damaged muscle and stimulate growth of new muscle. There’s no need to exceed 20 grams of protein unless your post-workout fuel is a regular meal (which may provide more than 20 grams). You’ll also want to consume carbohydrates to replenish glycogen stores.

Some of us sweat more than others. To determine how much you should drink to rehydrate after exercise, weigh yourself before and after your workout. Determine the difference between your pre- and post-exercise weight, then drink 16 ounces of fluid per pound you sweated out.

Excessive dehydration (loss of more than 2 percent of body weight) can lead to fatigue, decreased performance, increased risk of heat illness, and cardiovascular stress. For example, if you weigh 150 pounds before your workout and lose more than 3 pounds in sweat, you need to drink more fluids before and during your workout to avoid dehydration.

When hunger strikes post-workout, it’s convenient to reach for recovery sports bars and drinks. But often they are not as healthy as they seem. Many are laden with excess sugar, sodium, and calories that you don’t need after a workout. You can get the right combination of protein, carbohydrates, fluid, and electrolytes from whole foods and beverages:

  • Hardboiled egg with whole-wheat crackers
  • Fruit or vegetable juice
  • Smoothie made with milk or yogurt, bananas, and/or other fruit

Finding the right balance of food and drink before, during, and after a workout won’t happen overnight. You may have to experiment to find the combination of foods and drinks that work for you and your fitness goals.

It’s a good idea to check with your doctor before you drastically change your diet or exercise routine. Click here or call 214-645-8300 to request an appointment. In the meantime, try my tasty, healthy smoothie recipe to refuel.

Blueberry-Banana Smoothie


  • 1 cup unsweetened frozen blueberries
  • 1 medium banana (peeled and sliced)
  • ½ cup nonfat or low-fat plain or vanilla yogurt
  • 1 cup orange juice
  • 1 tablespoon peanut or almond butter
  • 1 teaspoon honey


Place all ingredients into a blender. Cover and blend until smooth and creamy. Serve immediately or refrigerate.


Three 1-cup servings

Nutrition Facts per serving

Calories: 168, Sodium: 38 mg, Potassium: 349 mg, Total Carbohydrate: 33 g, Fiber: 3 g, Protein: 5 g