Deciding Whether to Exercise While Fasting:
- Burn more fat. The major argument for working out while fasting is that you’ll burn more fat, and there are some studies to support this. When you’re eating regularly, your body draws energy from stored sugar or glycogen first and then from fat. When glycogen is low, you’re likely to start burning fat faster.
- Preserve your muscle. Keep in mind that your body can also break down protein and muscles for energy. When you skip meals before going to the gym, you’re likely to lose muscle mass along with fat.
- Maintain your metabolism. Prolonged fasting may also lower your metabolism as your body tries to use calories more efficiently to protect you from starvation. That’s especially true if you engage in intense activities. The result is that you may eventually find it more difficult to lose weight or keep it off.
- Avoid indigestion. On the bright side, you can forget about heavy meals interfering with your afternoon CrossFit class. Even when you’re not fasting, it helps to eat light within a few hours of your workout to avoid feeling lethargic.
- Watch your blood sugar. There is some evidence to suggest that fasting can affect insulin sensitivity and blood sugar levels. If you have conditions such as type 2 diabetes or metabolic syndrome, talk with your doctor before fasting. Ask them about exercising and any precautions you need to take.
Strategies for Working Out While Fasting:
- Plan your activities. Fasting affects some workouts more than others. In general, you may be comfortable doing light to moderate cardio. On the other hand, you could run out of steam attempting more intense cardio, strength, or endurance routines.
- Focus on restoration. Gentle yoga and other restorative practices could be an ideal solution if you’re concerned that taking days off would undermine your exercise habit. Browse the class offerings at local yoga studios or do your own slow static stretching.
- Drink water. Staying hydrated is even more important than usual when you’re fasting. Carry a water bottle and sip water throughout the day. As a bonus, you may feel less hungry.
- Consider your fueling window. Fasting takes many forms. You may go entire days without eating or just 16 hours or so at a time. Keep in mind the general rule to focus on complex carbohydrates before a workout and protein afterwards.
- Boost your electrolytes. Plain water is usually sufficient, but you may need to rebalance your electrolytes if you become dehydrated. Coconut water or sports drinks can help. Check the label if you’re concerned about sugar.
- Listen to your body. If you find yourself dizzy and light headed midway through your morning run, take a break. Honoring your body’s limits will help you to avoid injuries.
- Lighten up. Professional athletes may need to toil away at finding the precise formula for peak performance. If you’re just trying to stay fit and manage your weight, eating healthy and staying active will make you a winner.