Sharman, M. J., Volek, J. S., Fleming, J., Love, D. M., Avery, N. G., Gomez, A. L., & Kraemer, W. J. (2002). Exercise performance responses to a ketogenic diet. Medicine and Science in Sports and Exercise, 34(5), Supplement abstract 1313.

This study assessed the effects of a six-week ketogenic diet on maximal oxygen consumption, muscular power, and endurance capacity. Active men (N = 12) changed from a normal diet (48% CHO) to a ketogenic diet (8% CHO) while other men (N = 8) served as normal-diet controls. Cycle ergometer tests were used to evaluate physiological parameters.

Ss in the experimental group lost 2.2 kg while controls gained 0.1 kg. Neither group changed in VO2max. Absolute peak VO2, and peak and mean power output decreased significantly in the ketogenic group while controls remained unchanged. When analyzed relative to body weight, only peak power was altered significantly. Respiratory exchange ratio was lower in the ketogenic group during a 45-min timed ride indicating greater fat utilization while total work ouTput was significantly lower.

Implication. A ketogenic diet resulted in moderate decreases in absolute muscular power and endurance that may be partially due to decreased body weight.

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