The effect of a six-week ketogenic diet on VOp2smax, Wingate sprints, and prolonged exercise performance

The purpose of this study was to determine the effect of a 6-week ketogenic diet on maximal oxygen consumption (VO2max), high-intensity Wingate sprints, and work output during a 45-minute cycling bout. Twenty subjects were placed into either an intervention group (N=12) or a control group (N=8). Subjects in the dietary intervention group ingested a diet consisting of 61± 4% fat, 8± 3% carbohydrate, and 30± 5% protein while subjects in the control group were instructed to continue following their normal moderate carbohydrate diet. All subjects were instructed to maintain their current training status. On the first day subjects performed a VO2max test on an electronically braked cycle ergometer. On the second day subjects performed two 30-second Wingate sprints followed by a 30-minute rest. Following this subjects performed a 45-minute timed ride on a cycle ergometer set on isokinetic mode. Absolute VO2max decreased significantly (P