Football Players: A Precursor to Heat Cramps?

This observational study was designed to determine whether football players with a history of heat cramps have elevated fl uid and sodium losses during training. During a “two-a-day ” training camp, fi ve Division I collegiate football play-ers (20.2 ± 1.6 y, 113 ± 20 kg) with history of heat cramps (C) were matched (weight, age, race and position) with a cohort of teammates (19.6 ± 0.6 y, 110 ± 20 kg) who had never cramped (NC). Change in body weight (adjusted by fl uid intake) determined gross sweat loss. Sweat samples (forearm patch) were analyzed for sodium and potassium concentrations. Ad libitum fl uid intake was measured by recording pre- and post-practice bottle weights. Average sweat sodium loss for a 2.5-h practice was projected at 5.1 ± 2.3 g (C) vs. 2.2 ± 1.7 g (NC). When aver-aged across two practices within the day, fl uid intake was similar between groups (C: 2.6 ± 0.8 L vs. NC: 2.8 ± 0.7 L), as was gross sweat loss (C: 4.0 ± 1.1 L vs. NC: 3.5 ± 1.6 L). There was wide variability in the fl uid defi cit incurred for both C and NC (1.3 ± 0.9 vs. 0.7 ± 1.2%) due to fl uid intake. Sweat potassium was similar between groups, but sweat sodium was two times higher in C versus N