To eat or not to eat before a workout — it’s a dilemma faced by every fitness enthusiast. Some research has suggested that working out on an empty stomach allows you to burn more fat, while other studies have found no difference in fat loss. Other factors should also be taken into consideration, such as metabolism, muscle mass and performance.
Exercising on an Empty Stomach
Researchers at the University of Leuven in Belgium found that when cyclists trained without eating, they burned more fat than those who ate. If you haven’t eaten before exercising, your muscles don’t get the energy from carbohydrates like they usually do, according to the 2008 study published in "Medicine & Science in Sports & Exercise" and reported by Maria Chang. And with little carbohydrate to burn, the body instead burns fat.
But a study on the opposing side, published in the February 2011 issue of the "Strength and Conditioning Journal," showed that fat loss is the same irrespective of whether you eat before exercising.
Performance and Muscle Loss
Both studies showed that not eating before a workout decreases performance. The 2011 study found that exercising without eating may cause muscle loss, and likely will reduce exercise intensity and therefore overall calorie burn.
Similar results were found in another study in 1999 published in "Medicine & Science in Sports & Exercise." Researchers found that when subjects rode bikes on two mornings, once after a small breakfast and the other after fasting, the fasting subjects tired out more quickly and exercised 30 minutes less.
The muscle you may lose from exercising on an empty stomach can hinder overall fitness, said Cliff Latham, an exercise physiologist with nearly 25 years of experience as a fitness and weight-loss expert, university professor and coach. “For a distance runner, this is not an issue, but for the average person, not only is this detrimental, but it doesn’t help physique transformation,” he said.
Meals and Exercise
Whether you believe exercising on an empty stomach burns more fat or not, your eating decisions should be based on performance, rather than fat loss, according to Latham. “Your performance will lead to a much greater calorie deficit and thus, fat loss will occur along with improved performance,” he said. Also, not eating before exercise may lower your metabolism.
For the best results, Latham recommends eating small meals five or six times a day. “Eating on a more regular basis will help curb cravings and therefore large binge meals later at night,” he said.
Pre-Workout Foods
If you choose to eat before your workout, eat a light 200 to 300 calorie meal with some carbohydrates and protein, according to Health Services at Columbia University. Examples of such foods are egg whites, cottage cheese, yogurt and protein shakes.
“Keep the fat content low,” said Latham. "Find a drink or food that settles well in your stomach and doesn’t create nausea.” He said that a proper pre-workout meal will fuel working muscles with carbohydrates and increase the amount of free-floating amino acids to control muscle breakdown.
References
- "The New York Times"; Really? The Claim: Exercising on an Empty Stomach Burns More Fat; Anahad O'Connor; June 2011
- MSNBC.com: To Get Rid of Fat, Don’t Eat Before Workout; Maria Chang
- "The New York Times"; Really? The Claim: Exercising on an Empty Stomach Burns More Fat; Anahad O'Connor; April 2006
- Health Services at Columbia University: Does Exercising on an Empty Stomach Maximize Fat Burning?
- Cliff Latham; Exercise Physiologist; College Station, Texas
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