Periodic carbohydrate replacement during 50 min of high-intensity cycling improves subsequent sprint performance.

The purpose of this study was to investigate the effect of 7% carbohydrate-electrolyte (CE) drink on sprint capacity immediately following 50 min of high-intensity cycling. After an overnight 12-hr fast, 8 trained male cyclists performed two 50-min simulated time trials on a Monark stationary cycle ergometer. Subjects consumed either the CE or a flavored water placebo (PL) at 10, 20, 30, and 40 min during the time trial. At the conclusion of each 50-min time trial, subjects immediately performed a Wingate Anaerobic Power Test. Peak power, mean power, and minimum power were significantly higher for the CE trials, whereas mean RPE was significantly lower. Mean heart rate and fatigue index were not different between trials. These results suggest that sprint performance following a high-intensity simulated time trial of only 50 min can be improved with periodic consumption of CE during the ride, particularly following an overnight fast, when liver glycogen is likely to be low. These findings have implications for competitive cycling, where sprint capacity at the conclusion of a race is an important determinant of success.

[1]  E Hultman,et al.  Muscle glycogen during prolonged severe exercise. , 1967, Acta physiologica Scandinavica.

[2]  E. Hultman,et al.  Liver glycogen in man--the effect of total starvation or a carbohydrate-poor diet followed by carbohydrate refeeding. , 1973, Scandinavian journal of clinical and laboratory investigation.

[3]  L. Jorfeldt,et al.  Glucose metabolism during leg exercise in man. , 1971, The Journal of clinical investigation.

[4]  K. Rodahl,et al.  Use of respiratory quotients in assessment of aerobic work capacity , 1962 .

[5]  D. Costill,et al.  Effect of carbohydrate feedings on muscle glycogen utilization and exercise performance. , 1984, Medicine and science in sports and exercise.

[6]  A HENSCHEL,et al.  Maximal oxygen intake as an objective measure of cardio-respiratory performance. , 1955, Journal of applied physiology.

[7]  E Hultman,et al.  Diet, muscle glycogen and physical performance. , 1967, Acta physiologica Scandinavica.

[8]  E. Hultman,et al.  A study of the glycogen metabolism during exercise in man. , 1967, Scandinavian journal of clinical and laboratory investigation.

[9]  E. Coyle,et al.  Muscle glycogen utilization during prolonged strenuous exercise when fed carbohydrate. , 1986, Journal of applied physiology.

[10]  E. Coyle,et al.  Carbohydrate feeding during prolonged strenuous exercise can delay fatigue. , 1983, Journal of applied physiology: respiratory, environmental and exercise physiology.

[11]  Oded Bar-Or,et al.  The Wingate Anaerobic Test An Update on Methodology, Reliability and Validity , 1987, Sports medicine.

[12]  M. Millard-Stafford,et al.  Carbohydrate-electrolyte replacement during a simulated triathlon in the heat. , 1990, Medicine and science in sports and exercise.

[13]  J. C. Beasley,et al.  Effect of optimized and standard cycle ergometry on VO2 max in trained cyclists and runners. , 1989, Research quarterly for exercise and sport.

[14]  G. Brooks,et al.  Carbohydrate dependence during marathon running. , 1993, Medicine and science in sports and exercise.

[15]  A S Jackson,et al.  Generalized equations for predicting body density of men , 1978, British Journal of Nutrition.