Fasting and athletic performance: can fasting improve endurance and strength?

Fasting is a common practice in many cultures and religions, often used for spiritual or health reasons. However, the impact of fasting on athletic performance has been a topic of debate among researchers and athletes. In recent years, intermittent fasting has gained popularity among athletes as a way to boost their performance. But does fasting really improve endurance and strength?

What is intermittent fasting?

Intermittent fasting involves alternating periods of fasting and eating. There are several ways to do it, but the most common methods are:

• Time-restricted feeding: This involves eating only during a certain window of time, usually 8-10 hours per day, and fasting for the remaining 14-16 hours.
• Alternate-day fasting: This involves fasting for 24 hours every other day, and eating normally on non-fasting days.
• 5:2 fasting: This involves eating normally for five days a week, and restricting calories to 500-600 per day on two non-consecutive days.

Intermittent fasting and endurance performance

Endurance athletes have long used carbohydrate loading to improve their performance. However, recent studies have suggested that intermittent fasting may also be effective in improving endurance performance. One study published in the Journal of the International Society of Sports Nutrition found that time-restricted feeding improved cycling performance in trained cyclists, compared to a control group. Another study published in the Journal of Nutrition and Metabolism found that alternate-day fasting increased fat oxidation and improved endurance performance in cyclists.

Intermittent fasting and strength performance

While the evidence on the effects of intermittent fasting on endurance performance is promising, the evidence on strength performance is less clear. One study published in the Journal of Strength and Conditioning Research found that alternate-day fasting did not affect strength or power in resistance-trained men. Another study published in the Journal of Translational Medicine found that time-restricted feeding did not affect muscle strength or mass in resistance-trained men.

Benefits and risks of intermittent fasting for athletic performance

Intermittent fasting may offer several benefits for athletic performance, including improved endurance, fat oxidation, and metabolic flexibility. It may also have potential benefits for weight loss, insulin sensitivity, and inflammation. However, there are also potential risks associated with fasting, including decreased muscle mass, decreased immune function, and decreased recovery from workouts. It is important to consult with a healthcare professional or registered dietitian before starting an intermittent fasting regimen, especially if you are an athlete or have any medical conditions.

In conclusion, intermittent fasting may offer some benefits for endurance performance, but the evidence on its effects on strength performance is mixed. As with any dietary change, it is important to consult with a healthcare professional or registered dietitian before starting an intermittent fasting regimen.