Burke, L. M., Desbrow, B., Cox, G. R., Moquin, A., Martin, D. T., Burke, C. R., & Hawley, J. A. (2001). Effect of different caffeine intake protocols on metabolism and performance of prolonged cycling. Medicine and Science in Sports and Exercise, 33(5), Supplement abstract 249.

Competitive cyclists (N = 12) performed a cycling task (120 minutes at 70%VO2peak followed by a time trial of 7 kj/kg) on four occasions. Treatments were: 6 mg/kg caffeine taken 60 minutes pre-exercise; 6 x 1 mg/kg caffeine taken every 20 minutes throughout the steady state activity; 2 x 5 ml/kg Coca Cola consumed 100-120 minutes into the steady state activity and throughout the time trial; and placebo. Real-life activities associated with cycling, such as using CHO-drinks for fluid replacement, were followed in each treatment trial.

Compared to placebo, all caffeine treatments enhanced all performance factors over placebo. Intake of 6 mg/kg caffeine enhanced performance of the time trial after two hours of steady state cycling, the effect being independent of the timing of intake. The practice of replacing sports drinks with Coca Cola during the latter stages of an endurance event is also effective at enhancing performance late in exercise.

Implication. Caffeine ingestion enhances performance at the end of a very extended cycling endurance activity.

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