Athletic Training, Therapy, and Rehabilitation
Brendon P. McDermott, Douglas J. Casa, Susan W. Yeargin, Matthew S. Ganio, Rebecca M. Lopez and Elizabeth A. Mooradian
Previous field research has not identified sweat rates (SR), fluid consumption (FC), or the efficacy of an educational intervention (EI) for youth during football camp.
To measure hydration status and rehydration performance and examine EI using these data.
Observational with EI randomized comparison.
Thirty-three boys (mean ± SD: 12 ± 2 y, 52.9 ± 13.6 kg, 156 ± 12 cm) volunteered during a 5-d camp with 3 (~2-h) sessions per day (WBGT: 25.6 ± 0.5°C).
Main Outcome Measures:
Hydration status, SR, and FC.
Urine osmolality averaged 796 ± 293 mOsm/L for days 2-5. Game SR (1.30 ± 0.57 L/h) was significantly greater than practice SR (0.65 ± 0.35 L/h; P = .002). Subjects dehydrated during free time but matched fluid losses with FC (0.76 ± 0.29 L/h) during football activities.
Subjects arrived at camp hypohydrated and maintained this condition. They matched FC and SR during, but dehydrated when not playing, football. This may impair recovery and subsequent performance. Hydration EI seemed to have a positive influence on hydration practices.
Sandra Fowkes Godek and Arthur R. Bartolozzi
Daniel S. Moran, Tomer Erlich and Yoram Epstein
Individuals in the population who are not able to sustain heat and whose body temperature will start rising earlier and at a higher rate than that of others, under the same conditions, are defined as “heat intolerant.”
The applicability of the heat tolerance test (HTT) in identifying individuals’ tolerance/intolerance to heat is presented.
HTT is performed according to the following protocol: 120 minutes exposure to 40°C and 40% relative humidity in a climatic chamber while walking on a treadmill, dressed in shorts and T-shirt, at a pace of 5 km/h and 2% elevation. Rectal temperature and heart rate are continuously monitored, and sweat rate is calculated.
Results and Conclusion:
The HTT that is based on controlled exposure to an exercise-heat stress is an applicable and an efficient tool in differentiating between a temporary and permanent state of heat susceptibility.