6 Fasting Tips for Fitness Fans

Fasting has proven health benefits for the average person. But what if you’re exercising heavily, playing lots of spots, or engaging in any other type of strenuous physical activity? Can you still fast?

Ben Greenfield
5-minute read
Episode #148

In her episode What Are the Health Benefits of Fasting, my fellow Quick and Dirty Tips host Nutrition Diva tells you how fasting can reduce oxidative stress and inflammation in cells, prevent and repair DNA damage, increase longevity, and reduce your risk of dying from chronic diseases such as diabetes and heart disease. She also gives some great fasting tips for the average person.

But what if you’re exercising heavily, playing lots of spots, burning a high number of calories, or engaging in any other type of higher-than-average physical activity? Does fasting still work, or is it simply too hard on your body to restrict calories and work on fitness at the same time?

In this episode, you’re going to get 6 fasting tips for fitness fans, discover how fasting can help you lose fat, gain muscle and recover faster, and learn how to combine fasting and exercise without doing damage to your body.


Why Fasting Works

While the majority of exercise nutrition recommendations tell you to shove carbohydrates and protein down your gullet as soon as possible after you finish a workout, there is actually quite a bit of evidence that not eating can also have a recovery effect. In one study on cyclists3 weeks of overnight-fasted workouts increased post-workout recovery, while maintaining lean muscle mass, lower body fat, and performance. Another study on endurance athletes suggested that fasted training upregulates muscle protein translation, allowing for faster muscle recovery and growth - especially compared to athletes who ate carbohydrates before training.

See also: Should You Eat Before or After a Workout?


There are other benefits to fasting. A 2009 study found that subjects who lifted weights in a fasted state had nearly double the muscle-building response when they ate their post-workout meal. One way to think of this is that by providing nutrients to the body, exercise in a fed state may be experienced by the body as less stressful compared to exercise in a fasted state. Since the body is stressed slightly less, it may not actually get quite as fit. In other words, some stress is actually good for building muscle, and just like you need to lift heavy weights to create stress, you may also be able to get some added benefit by lifting in a fasted state.

6 Steps to Fasting for Fitness Fans

However, there can be a fasting paradox if you’re a very active person. After all, you need to give your body enough nutrients to allow for adequate hormone formation and muscle repair and recovery, and excessive calorie restriction can result in energy deficits and the unpleasant side effect of muscle wasting. So while you can get away with fasting regularly or for long periods of time if you’re a monk sitting cross-legged on a mountaintop for days on end, you simply can’t do the same thing if you’re swimming, biking, running, weight lifting, and any other strenuous exercising to get lean, toned, and strong!


About the Author

Ben Greenfield

Ben Greenfield received bachelor’s and master’s degrees from University of Idaho in sports science and exercise physiology; personal training and strength and conditioning certifications from the National Strength and Conditioning Association (NSCA); a sports nutrition certification from the International Society of Sports Nutrition (ISSN), an advanced bicycle fitting certification from Serotta. He has over 11 years’ experience in coaching professional, collegiate, and recreational athletes from all sports, and as helped hundreds of clients achieve weight loss and fitness success.