Carbohydrates & Metabolism During Athletic Activity

Carbohydrates power you through your swimming workout.
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If you're looking for an excuse to eat more bread and pasta, grab your sneakers and get moving. Carbohydrates fuel your muscles during exercise. The amount of carbohydrates you need depends on the frequency of your workout as well as their duration and difficulty. If you're active, you need to eat enough carbohydrates to keep your energy up, but choose your carbohydrates wisely.

Carbohydrate Metabolism

    When you eat carbohydrates, they are converted by your body into glucose, a simple sugar. This raises your blood sugar levels and triggers your pancreas to release insulin. Insulin moves the glucose to your cells where it gives you energy right away. Any glucose that your body does not need immediately travels to the liver and muscles where it’s stored as glycogen.

Carbohydrates During Exercise

    With exercise, your body calls upon your stored carbohydrates. Immediately, your levels of epinephrine and norepinephrine rise, which increases glucagon. Glucagon is converts glycogen back into glucose. This glucose is released into your blood so that you have the energy you need to work out. Once the glycogen is gone from your working muscles, your body pulls glycogen from the muscles you’re not using so that you have a little extra fuel to keep going.

Carbohydrate Reserves

    You keep leftover carbohydrates in your liver with a little extra stored in your muscles. The way in which you use carbohydrates during exercise depends on how much you have stored, the intensity and length of time of your exercise and whether you eat additional carbohydrates during exercise. When you exercise at a higher intensity, you use carbohydrate stores because your body can get access to those more quickly than fat or protein stores. You know that your carbohydrate stores are gone when you feel like you cannot move another inch. You can prevent fatigue by eating a high-carbohydrate meal an hour before you workout.


    Carbohydrates should be 40 to 60 percent of your daily calories. If you are extremely active, shoot for the higher end of that number so that you have the necessary energy. Choose complex carbohydrates over simple carbohydrates. Complex carbohydrates contain nutrients and fiber. Simple carbohydrates are typically processed and contain refined sugar. This makes them high in calories but low in nutrients. Opt for fruits vegetables and whole grains rather than white breads, cookies and crackers.

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