5 intermittent fasting tips for athletes
Intermittent fasting and time-restricted eating are some of the most popular nutrition trends these days. Maybe you’ve got a friend or trainer expounding on how it slims you down and helps you maintain muscle. After all, the fittest guys in Hollywood—from Hugh Jackman and Chris Pratt to newly minted superhero Jumail Nanjiani—all swear by it. And recent research published in the journal Cell Metabolism suggests that eating within a 10 hour window could help rev up your metabolism while reducing the risk of heart disease as well.
For the uninitiated, intermittent fasting is the practice of eating within a certain window and fasting the rest of the time (typically 12 to 18 consecutive hours, with 6-12 hour windows when eating is allowed). Even if you don’t change the content of your diet, by controlling the time period in which your calories are consumed, you give your body and digestive systems a pause so your body can focus on other tasks. But how do you do this and not affect your training? After all, athletes need fuel. Herewith, some expert tips.

Don’t go overboard
When trying to use fasting to improve athletic performance, less is usually more, says fitness expert and author of The Primal Blueprint, Mark Sisson. He’s found that as athletes fast, they notice benefits like faster times and less body fat. They feel lighter and faster so they push it further and fast for longer. But this only works to a point. If you go too long without fuel, you’ll see your performance drop significantly.

Up your protein
Protein is important when you’re training, but it will also help you manage hunger pangs as you transition to longer periods of fasting since it increases gut hormones that keep you feeling full. What’s more, the amino acids in protein will improve focus to keep you motivated and clear-headed.

Track it
Kevin Rose, the Digg founder and tech entrepreneur, developed a simple-to-use app for fasting called Zero. Rose told me he got interested in fasting when he learned that Hugh Jackman used a daily 16-hour fast to lean up for his role in Wolverine. Personally, I find the app incredibly helpful. Just opening the app and hitting the start button (which initiates the clock that times your fast) helped put me in the right frame of mind. I also liked getting a notification sent when I hit my fasting goal. Once that alert chimed, I knew I was clear to start refueling.

Monitor fasted exercise
Fasted exercise is still somewhat controversial. The idea is that when carbohydrate stores are depleted, the body relies on fat stores for energy. In turn, this may help you become more efficient at burning fat for fuel—which is key in endurance races. Some runners and coaches swear by it, but the research is still mixed. Recent studies have shown that training with limited carbohydrate availability may lead to some metabolic boosts, but doesn’t improve performance. Just make sure it’s not wearing you down and be sure to refuel and break your fast shortly after a workout.

Boost your growth hormones
Sisson recommends continuing your fast after a workout every so often to mix things up. “This enhances secretion of growth hormone, which fasting already elevates,” he says. The hormone is known to supercharge immunity while building muscle and cartilage while aiding in recovery. “Just don’t make this an every-workout habit … diminishing returns and all.”