Should you work out on an empty stomach? (2024)

FAQs

Should you work out on an empty stomach? ›

The final verdict? Exercising in a fasted state may burn some quick body fat, but it's not the best option for your body in the long-run. Eat a small snack or meal before and after your workout to ensure that you're properly fueled to perform your best in the gym and recover quickly when you get home.

It's often recommended that you work out first thing in the morning before eating breakfast, in what's known as a fasted state. This is believed to help with weight loss. However, working out after eating may give you more energy and improve your performance.

Working out on an empty stomach can pose risks, especially if not done correctly or if one has specific health conditions. Risks such as hypoglycemia, i.e., low blood sugar levels can cause dizziness, weakness, and fainting during exercise, potentially leading to accidents or injuries.

Even if you manage to push through a workout made difficult by a lack of fuel, your muscles can't rebuild, and your body may even resort to using the protein from your muscles themselves. Runners that chronically underfuel and overtrain are at risk of developing Relative Energy Deficiency in Sport (RED-S).

If your workout for the day involves heavy lifting, you can do so in a fasted state, but you should prioritize eating a meal directly following your workout. Unlike a burst exercise session, heavy lifting puts enough stress on the body to warrant an immediate refeed.

Working out on an empty stomach won't hurt you—and it may actually help, depending on your goal. But first, the downsides. Exercising before eating comes with the risk of “bonking”—the actual sports term for feeling lethargic or light-headed due to low blood sugar.

Morning exercise can help you make healthier choices.

That early morning sense of accomplishment can also help you have a healthier day. “When you get up and exercise, you establish a healthier mindset, which makes you more mindful of what you eat during the day,” she explains.

As a general rule of thumb, it's best not to eat immediately before a workout because while your muscles are trying to do their "thing," your stomach is trying to simultaneously digest the food in your stomach. These competing demands are a challenge for optimal performance.

Studies suggest that eating or drinking carbohydrates before exercise can help you do better during your workout. And the carbohydrates may allow you to work out for a longer time or at a higher intensity. If you don't eat, you might feel slow-moving or lightheaded when you exercise.

Will I lose muscle if I workout on an empty stomach? ›

Exercising in a fasted state may help burn more fat, but it can also cause the body to burn muscle for fuel in addition to fat. Even if the percentage of muscle burnt is comparatively small, it can be detrimental to the long-term success of any weight- or fat-loss program.

The Truth About Fasting Exercise

The truth is that exercising in a fasted state will indeed help you burn fat calories faster. You may see the number on the scale decrease. However, exercising on an empty stomach will also cause you to lose lean muscle mass at the same time, which can hinder long-term weight loss.

Yes, eating less with a low-calorie diet puts you on the fast track to weight loss—and an intense exercise routine leads to increased metabolism and decreased body fat. In reality, a crash diet and overzealous exercise routine can be hard to maintain which may lead to more weight gain in the future.

Studies have shown that working out at 7 a.m., compared to later in the afternoon or evening, may help individuals get more quality sleep at night. One more argument making the case for a workout first thing in the morning is that exercising on an empty stomach could burn more fat.

It can help burn body fat

Some studies suggest that you may burn up to 20% more fat when exercising on an empty stomach. Interestingly, while you burn more fat, you don't burn more calories. Increased fat burning is achieved by changing the source of where the calories are burned.

“There is insufficient data proving that fasted training leads to better fat loss over time, which is one of its common claims,” says Life Time master trainer and nutrition coach Joe Meier, CSCS, PN2. “Choosing between fasted versus fed training simply comes down to an individual's preferences and goals.”

Studies suggest that eating or drinking carbohydrates before exercise can help you do better during your workout. And the carbohydrates may allow you to work out for a longer time or at a higher intensity. If you don't eat, you might feel slow-moving or lightheaded when you exercise.

“Some research indicates that fasted cardio can lead to fat loss,” explains Schlichter. Without food that morning, your body doesn't have available glucose, which is its go-to source of fuel to give you that zip during cardio. Still, your body needs to pull fuel from somewhere, so it will tap into fat stores instead.

Exercising on an empty stomach can help you burn more body fat for fuel. When you eat right before exercising, your body is going to first use the calories you just consumed for fuel.

That plan is called the 30-30-30 rule. It's a simple but catchy idea that encourages you to eat 30 grams of protein within 30 minutes of waking up and then get 30 minutes of low-intensity exercise. The 30-30-30 rule now has millions of followers on TikTok.