Endurance athletes typically fuel their effort with a high-carbohydrate diet, but some have had success with converting their body to burning fat for fuel. High-fat carbohydrate restricted diets can increase fat oxidation in endurance athletes. A study published in the International Journal of Sports Physiology and Performance looks at one athlete’s attempts to tweak the fat for fuel approach by adding carbs.
The subject for this study placed well in numerous races consuming approximately 80 grams of carbohydrates per day and drinking only water while training and competing. For 3 weeks, he added 60 grams of carbohydrates per hour during 8 high-intensity training sessions.
With the addition of these carbohydrates to his standard diet, the subject’s 20 km time trail performance improved by 2.8%, which is very significant. There was a small 1.6% increase in 4 minute sprinting power, but no change in 30 second sprinting power.