Harvard Medical School Commentaries: Food for Thought

Mar42011

How To Eat for Endurance Exercise

by Kerri Parker, M.S.
Brigham and Women's Hospital

The Boston Marathon, one of the world's oldest and most famous 26.2-mile races, celebrates its 115th year this April.

Endurance sports are growing in popularity. Last year over one million runners with various abilities participated in marathons and half marathons around the country. No matter their level of experience or skill, they all have one thing in common: a need for the best dietary fuel to perform to the fullest potential.

Whether you run marathons or half marathons, or participate in endurance cycling, swimming or triathlons, what you eat before, during and after exercise is crucial to performing your best during training and racing.

Follow these simple strategies and see your energy and athletic capacity soar.

 

What Do I Eat Before a Workout?

Eating before a workout can be tricky. You want to eat enough food to fuel your workout, but not so much that you feel heavy, bloated and sluggish.

The best pre-workout snack or meal has easily digestible, low-fiber carbohydrates, a small amount of protein and little or no fat. Carbohydrates will provide the glucose (sugar) your muscles need for a workout. Protein slows down the release of glucose so your working muscles stay fueled for the long haul.

What you eat and how much you eat will depend on how long your workout lasts.

Exercise time

What to eat and drink

When

Examples

Less than 75 minutes

100- to 200-calorie snack and glass of water

1-2 hours before workout

  • Banana with ½ cup nonfat or low-fat yogurt
  • 1 slice whole grain toast with 1 tablespoon nut butter and a drizzle of honey
  • 1 cup of whole grain cereal with ½ cup nonfat or 1% milk or soy milk
  • 1 cup fruit with ½ cup nonfat or low-fat cottage cheese
  • ½ whole wheat bagel with 1 tablespoon nut butter
  • 1 small oatmeal cookie with small glass of nonfat or low-fat milk or soy milk
  • 1/3 cup fruit and trail mix with nuts

More than 75 minutes

A moderate-sized, low-fat meal


A 100- to 200-calorie snack with a glass of water

    4-5 hours before workout

    1-2 hours before workout

    • Low-fat meal that includes carbohydrate and protein; no fried, greasy or high-fat foods

    If you exercise early in the morning, you may find it difficult to eat anything substantial before a workout. If so, eat a small 100- to 200-calorie snack just before your workout. Pay extra attention to eating and drinking adequately during exercise if your workout lasts more than 75 minutes. (See below.)

     

    What Do I Eat During a Long Workout?

    During a long workout your body needs a regular supply of glucose to continue running strong. The glucose comes from the carbohydrates you eat and from the glucose that is stored in your muscles and liver. (Stored glucose is called glycogen.)

    When your body runs out of glycogen you may "hit the wall" or experience extreme fatigue. This can quickly end a workout or race. To avoid this common pitfall, reach for easily digestible simple carbohydrates.

    Exercise time

    What to eat and drink

    When

    Examples

    Less than 75 minutes

    As long as you followed the pre-workout tips, you should only need sips of water.

    On a particularly hot day, you may want to drink a diluted sport drink to help replace electrolytes lost through sweat.

    More than 75 minutes

    After the first 60 minutes, eat or drink 25-60 grams of carbohydrate (100-250 calories) for each additional hour you work out. (The amount depends of a person's weight. For a 110-pound woman, 25 grams per hour may be enough while a larger man may need closer to 60 grams.)

    Make sure you keep drinking 3-6 ounces of water every 15-20 minutes. Carry a bottle with you or stash one along your route.

    • Pre-packaged sport gel
    • ½ high-carbohydrate, low-protein, low-fat sport/energy bar, such as PowerBar or Clif Bar
    • Bite-sized sport/energy bars or gummies, such as Shot Bloks, Gu Chomps or PowerBar Bites
    • Medium banana
    • Large orange

     

    What Do I Eat After a Long Workout?

    If you are like many of us, your post-workout routine probably consists of a quick shower and a mad dash out the door or back to work. However, your post-workout nutrition is very important for making your body ready for its next workout.

    After a long, hard workout, your body is out of glycogen and your muscles are broken down. To begin refilling your energy stores and rebuilding your muscles, you need to eat and drink within the first hour after your workout — even if you don't feel hungry.

    Carbohydrates will refill the glycogen stored in your muscles. Protein will repair and rebuild damaged muscle cells.

    Exercise time

    What to eat and drink

    When

    Examples

    Less than 75 minutes

    Eat a 100-300 calorie snack with carbohydrate and protein; drink 16 ounces of water

    Within 60 minutes of finishing workout

    • Whole grain cereal with skim or low-fat milk and a small handful of nuts
    • Whole wheat toast, fruit, 1 scrambled egg or 2 egg whites
    • Fruit salad with 8 ounces of plain Greek yogurt
    • Fresh fruit with peanut butter and 8 ounces of skim chocolate milk
    • Bean or lentil soup with whole wheat crackers
    • Bean and cheese burrito with whole wheat tortilla
    • Low-fat cottage cheese with sliced fruit and whole wheat crackers
    • 8-12 ounce smoothie (fruit, milk or yogurt, ice, 1-2 tablespoons peanut butter or whey protein powder)

    More than 75 minutes

    Eat a 100-300 calorie snack with carbohydrate and protein; drink 16 ounces of water

    A regular 400-500 calorie meal and more fluid

    Within 30 minutes of finishing workout

    Within 1-2 hours of finishing workout

    • Any of the snacks listed above
    • 400-500 calorie meal should include a combination of:
      • Bite-sized sport/energy bars or gummies, such as Shot Bloks, Gu Chomps or PowerBar Bites
      • Medium banana
      • Large orange

     

    Final Thoughts

    As athletes, we must remember that what and when we eat directly affects our strength, stamina and ability to recover from a hard effort. Practicing these nutrition principles before, during and after your workouts will guarantee increased energy and performance.

     

    Kerri Parker, M.S. is a dietetic intern at Brigham and Women's Hospital. She graduated with a B.S. in Kinesiology and an M.S. in Nutrition from California Polytechnic University, San Luis Obispo. She has been a long-distance runner and triathlete for the past 10 years.

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