What Is Bonking?

EndurElite Chief Endurance Officer Matt Mosman discusses what bonking is and how you can prevent it from happening to you during endurance training and racing

What Does "Bonking" Mean?

In the simplest sense bonking is when muscle and liver glycogen becomes depleted and when carbs aren’t consumed during endurance exercise to keep blood glucose elevated.

When Does Bonking Happen?

Bonking usually occurs in longer duration events like the marathon where intensity is 75-85% VO2 max.

What Does Bonking Feel Like?

Symptoms of bonking include whole body fatigue, heavy legs, confusion, dizziness, and been a grumpy goat.

How To Prevent Bonking

To prevent bonking follow these steps.

  1. Carb load 3 days before a big race - 8 to 10 grams of carbs per kg bodyweight daily.
  2. 3-4 hours before the race eat 200-300 grams of carbs to “top off” glycogen stores.
  3. Eat another 50 grams of carbs 60 minutes before the start of the race.
  4. If the race is over an hour consume 30-90 grams of carbs (sports drinks, gels, chews) an hour (duration and intensity dependent) to keep blood glucose elevated and to help spare glycogen.
  5. After the race consume 1-1.5 grams of carbohydrate per kilogram body weight during the first 30 minutes and every 2 hours for at least 4-6 hours after that.

Take home point? EAT ALL THE CARBS!