Carbohydrate feedings during team sport exercise preserve physical and CNS function

WINNICK, J. J., J. M. DAVIS, R. S. WELSH, M. D. CARMICHAEL, E. A. MURPHY, and J. A. BLACKMON. Carbohydrate Feedings during Team Sport Exercise Preserve Physical and CNS Function. Med. Sci. Sports Exerc., Vol. 37, No. 2, pp. 306-315, 2005. Purpose: This study was designed to examine the effect of carbohydrate (CHO) feedings on physical and central nervous system (CNS) function during intermittent high-intensity exercise with physical demands similar to those of team sports such as basketball. Methods: Twenty active men (N = 10) and women (N = 10), with experience competing in team sports, performed three practice sessions before two experimental trials during which they were fed either a 6% CHO solution or a flavored placebo (PBO). Experimental trials consisted of four 15-min quarters of shuttle running with variable intensities ranging from walking (30% VO2max) to running (120% VO2max) to maximal sprinting, and 40 jumps at a target hanging at 80% of their maximum vertical jump height. Subjects received 5 mL(.)kg(-1) of fluid before exercise and 3 mL(.)kg(-1) after exercise, in addition to 3 mL(.)kg(-1) over a 5-min span after the first and third quarters, and 8 mL(.)kg(-1) during a 20-min halftime. During each break, the subjects performed a battery of tests measuring peripheral and CNS function, including 20-m sprints, a 60-s maximal jumping test, internal and external mood evaluation, cognitive function, force sensation, tests of motor skills, and target-jumping accuracy. Results: Compared with PBO, CHO feedings during exercise resulted in faster 20-m sprint times and higher average jump height in the fourth quarter (P < 0.05). CHO feedings also reduced force sensation, enhanced motor skills, and improved mood late in exercise versus PBO (P < 0.05). Conclusion: These results suggest that CHO feedings during intermittent high-intensity exercise similar to that of team sports benefited both peripheral and CNS function late in exercise compared with a flavored placebo.