A comparison of the effects of fluid and electrolyte replacement schedules on work performance and circulatory stress in 30 members of a high school football team

Abstract

The effects of administration of glucose-electrolyte solution using three different schedules of administration were investigated in 30 high school football players. Environmental conditions during the experiment were 90-95° and 60-62% relative humidity. Schedule I consisted of consumption of fluid ad libitum. Schedule 2 consisted of administration of 120 milliliters of fluid every 15 minutes. Schedule 3 consisted of administration of 240 milliliters of fluid every 15 minutes. Fluid consumption during schedule 1 was 0.81 liters, 0.96 liters during schedule 2, and 1.92 liters during schedule 3. Regardless of the schedule followed, weight loss remained approximately 3 kilograms. This deficit of fluid volume was reflected in all groups as a decrease in VO2(max). VO2(max) decreased 31% in schedule 1, and 25 and 23% in schedules 2 and 3, respectively. Physical performance, also measured by time needed to complete a 300-meter obstacle course, increased 36% in schedule 1 and decreased 13 and 28% in schedules 2 and 3, respectively.