Avoid The Bonk: Fuel Your Brain
- By Paul Moore
- Published April 7, 2011
Have you ever bonked in a workout or race while feeling great? Of course not. And there’s a reason for that. Exercise scientists used to believe that “perceived effort”, or how hard exercise feels, was a peripheral phenomenon that had nothing to do with performance and fatigue. More recently, however, researchers have learned that perceived effort is actually a major cause of fatigue during exercise. Simply put, when the level of suffering required to sustain a certain pace becomes unbearable, we slow down.
Training, motivation, and other factors increase performance in part by making exercise at any given intensity feel easier. Nutrition can do the same. The “big three” nutrients affecting perceived effort are carbohydrate, protein, and caffeine.
Carbohydrate
Studies have shown that endurance performance is increased when athletes merely rinse their mouths with a sports drink periodically during exercise instead of swallowing it. It appears the carbs in the sports drink activate carbohydrate receptors in the tongue, which communicate with a part of the brain that regulates perceived exertion. As a result, exercise feels easier and performance increases.
Rinsing your mouth with a sports drink is not a complete substitute for actually swallowing it, as drinking rehydrates in addition to supplying energy. But in situations where it’s difficult to drink a lot, such as during high-intensity running, rinsing your mouth with a sports drink may be a good complement to ingesting it.
Protein
A series of studies led by Michael Saunders at James Madison University has shown that a sports drink containing carbs and protein in a 4:1 ratio (Accelerade®) increases endurance more than a conventional sports drink containing carbs and no protein. These studies have also shown that the beneficial effect of consuming protein with carbs during exercise is linked to a reduction in perceived exertion.
How does protein make exercise feel easier? One possibility is that ingesting protein with carbs during exercise increases amino acid levels in the blood. There is evidence that elevated blood amino acids delay brain fatigue during exercise. Another possibility is that protein reduces perceived exertion by reducing muscle damage. Carb-protein Accelerade is in fact proven to reduce muscle damage during exercise compared to carb-only sports drinks.
Caffeine
Fifteen years ago, before the role of the brain in exercise performance was much appreciated, scientists believed that caffeine enhanced endurance exercise performance by increasing fat burning. It is now known that caffeine enhances endurance performance by blocking adenosine receptors in the brain and thereby reducing perceived effort. By reducing the perception of effort associated with exercise at any given intensity, caffeine allows athletes to go faster before they feel they’re working as hard as they can.
Matt Fitzgerald is a certified sports nutritionist and the author of numerous books for endurance athletes, including “Racing Weight: How to Get Lean for Peak Performance”
To Download The Complete Endurance Nutrition Handbook From PacificHealth Laboratories Click Here (1.2mb)
FILED UNDER: All / Nutrition TAGS: Bonk / brain / Caffeine / carbohydrate / matt-fitzgerald / mental / perceived-effort / power / Protein / strength
Paul Moore
Paul Moore is the Online Editor for Triathlete Europe. When not glued to a computer he can be found writing books - most recently Ultimate Triathlon: A complete training guide for long-distance triathletes which you can buy on Amazon
