Should I Work Out When I’m Fasting?

There are a number of different types of fasts, from ones that last hours to ones that last days, so whether it’s safe to work out when fasting depends on how long you fast. If you’re doing a fast that’s longer than a day, you’re significantly lowering your energy level. For intermittent fasting, which can be from several hours to a day, the answer is a bit murkier. Most people choose a pattern of eating during an eight-hour window and fasting the other sixteen when they opt for intermittent fasting. It’s not necessary to give up your activity for that type of fast or give up all types of exercise even on a longer fast. Before you start any fast, always check with your health care professional.

What happens to your body when you fast?

When you eat carbohydrates, your body converts them and stores them as glycogen. Overnight your body is using the stored glycogen, since you’re not eating. It’s why the first meal of the day is called, “break-fast.” You’re breaking the fast of the previous night. There are good reasons to exercise in the morning before you eat and good reasons not to do that. If you don’t eat, but opt for intermittent fasting, where you extend your fasting time to far later in the day, your body will burn more fat for energy due to low glycogen reserves. It also could burn more protein in the form of lean muscle tissue. The less lean muscle tissue you have, the slower your metabolism, so there’s no clear cut answer to which is best.

Have your workout match your fast.

Are you working out every other day? If you fast for hours or a day, have your workout mesh with the days you don’t fast. If you’re doing intermittent fasting, exercise during your eight hour window where you eat. Have a small carb and protein snack before you workout and one within an hour after you finish. You’ll have the glycogen available to make your workout productive, keep your metabolism strong and the protein afterward can help with recovery.

Longer fasts require more planning.

You definitely won’t want to do a high intensity workout if you’re fasting longer than a day or two. That doesn’t mean you can’t exercise. Going for a brisk walk or doing some light exercising can be beneficial. If you feel light-headed when you workout, it’s your body’s way of saying you’re overdoing. Don’t add to the struggle.

  • If you’re breaking your fast right before you workout, keep the food intake small and eat at least a half hour before working out. You can eat a full meal if you’re eating 1-3 hours before exercising.
  • For intermittent fasting, stick with higher protein snacks, to help boost muscle growth and repair. Put nut butter on an apple for the perfect combination of protein and carbs.
  • Even if you’re fasting, remember to drink plenty of water. Hydrating frequently can help you stick with a fast, keep you feeling fuller and ensure your lack of energy won’t be due to mild dehydration.
  • Save your biggest meal for after an intense workout. Try to make it within the first half hour to an hour afterward. Your meal should have at least 20 grams of protein.

For more information, contact us today at Wholly You Fitness


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