7 Steps to Avoid the Dreaded Bonk

Do you know how long it takes to run, swim or cycle through your fuel stores? Though the timing varies—and depends on the sport, environmental conditions and nutrition that follows—it takes 1 to 3 hours to use up your fuel stores.

It's during this time period that your body begins to experience muscle glycogen depletion, which leads to fatigue. That's when you "hit the wall" or "bonk." 

More: How to Beat Marathon Fatigue

When this happens you can't focus on the exercise task at hand. You may experience lightheadedness, poor concentration, irritability and even become disoriented during exercise. This makes exercise harder, and coordination and judgment suffers, which leads to poor performance.

Don't let "the bonk" ruin your chance to achieve a PR or cross the finish line strong. Learn why it happens so you can avoid it at your next event.

Why You "Hit the Wall"

Blood glucose, which is maintained by your liver's glycogen stores, is your brain's only fuel source. When your brain isn't fueled, you can't perform. Carbohydrates replenish and fuel your muscle and liver glycogen stores. But don't be fooled: Carbo-loading the night before the race doesn't prevent bonking.

Proper nutrition needs to be practiced daily to provide your body and brain with the energy it needs to perform. This energy should come from a combination of carbohydrate, protein and fat in the days and hours leading up the event.

Here are seven ways to ensure you get all the energy you need to avoid the wall and run straight through to the finish line.

More: How Runners Can Benefit From Fatigue

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About the Author

Michelle Ulrich

Michelle Ulrich, MS, RD works as a clinical dietitian at Sharp Memorial Hospital in San Diego, California. She's also the sports dietitian for ETA Coach, an endurance coaching company. She has a passion for food, nutrition and sports.

Michelle Ulrich, MS, RD works as a clinical dietitian at Sharp Memorial Hospital in San Diego, California. She's also the sports dietitian for ETA Coach, an endurance coaching company. She has a passion for food, nutrition and sports.

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