What is Bonking? The Runner's Guide to Hitting the Wall

What Does "Bonking" Mean in Running?

If you've ever been in the middle of a long run and suddenly felt like you couldn't take another step, you might have experienced what runners call "bonking" or "hitting the wall." This phenomenon is one of the most dreaded experiences in endurance sports.

The Science Behind Bonking

Bonking occurs when your body runs out of glycogen—the stored form of carbohydrates in your muscles and liver. Your body can typically store enough glycogen for about 90 minutes to 2 hours of intense exercise. Once these stores are depleted, your body has to rely more heavily on fat for fuel, which is a much slower process.

Common Signs of Bonking

Sudden fatigue that feels overwhelming
Difficulty maintaining pace
Mental fog or confusion
Shaky legs
Extreme hunger
Irritability or emotional changes

How to Prevent Bonking

1. Proper Fueling Before Your Run

Start your run with full glycogen stores by eating a carbohydrate-rich meal 2-3 hours before your workout.

2. During-Run Nutrition

For runs longer than 60-90 minutes, consume 30-60 grams of carbohydrates per hour through energy gels, sports drinks, or other easily digestible foods.

3. Train Your Gut

Practice your race-day nutrition during training runs to ensure your stomach can handle fuel while exercising.

4. Pace Yourself

Starting too fast depletes glycogen stores more quickly. Run at a sustainable pace, especially in the early miles.

Recovery from Bonking

If you do bonk during a run:

Slow down significantly or walk
Consume fast-acting carbohydrates immediately
Hydrate well
Don't push through—listen to your body

Conclusion

Understanding what causes bonking and how to prevent it is essential for any distance runner. With proper training, nutrition, and pacing strategies, you can avoid hitting the wall and have a successful race day.

Want to learn more running terms? Check out our complete dictionary of running slang.