Player-Reported Fluid Intake and Measured Hydration Status of NCAA Division I Football Players During Fall Training Camp
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Background: Hydration is critical to the health and sports performance of athletes. Position statements from the American College of Sports Medicine, the National Athletic Trainers’ Association, and the Academy of Nutrition and Dietetics include recommendations for adequate fluid intake to prevent dehydration. Dehydration is associated with physiologic changes, including increased core body temperature and heart rate that can lead to performance deficits. Decreases in muscle strength can occur at levels of 5% dehydration, and reductions in aerobic power and endurance take place at levels of 3-4% dehydration. Despite the importance of hydration, athletes frequently participate in training or competition in a dehydrated state. Methods: This study was designed to assess the fluid intake, hydration status, and levels of fatigue and muscle soreness among collegiate athletes. The sample consisted of forty-six National Collegiate Athletics Association (NCAA)-Division I (D1) male football athletes at the University of Washington who participated in 2016 fall training camp. The athletes completed a daily survey to report fluid intake (liters) during the previous day, level of muscle soreness (5-point scale), and level of fatigue (5-point scale). Hydration status was assessed using urine specific gravity (USG) testing on three occasions during fall training camp. Hydration status was determined based on the American College of Sports Medicine and National Athletic Trainers' Association criteria: (1) euhydrated, which was urine specific gravity less than 1.020; (2) hypohydrated, from 1.020 to 1.029; and (3) significantly hypohydrated, equal to or more than 1.030. Player position and year on the team was also recorded for each athlete. Results: Fluid intake (L/day) and USG of the football athletes were suggestive of appropriate hydration strategies and adequate hydration levels during fall training camp. 81.1% of athletes had fluid intake levels above 3.7 liters of fluid per day (p < 0.001), and 64.9% of athletes had urine specific gravity (USG) below 1.020 (p < 0.0001), indicating a state of hydration. USG was found to be significantly inversely associated with fluid intake. Mean urine specific gravity was lower for athletes with higher fluid intake (R2 = -0.0019, p < 0.0001). Player position or year on the team was not associated with fluid intake (L/day) or USG. Muscle soreness and fatigue (5-point scale) were found to be positively associated with USG, with marginal (p=0.064) significance and statistical significance (p=0.019), respectively. Levels of fatigue and muscle soreness increased as USG increased, suggesting more severe fatigue and soreness in states of hypohydration. Conclusion: American football athletes are at increased risk for dehydration due to high sweat rates, heavy protective equipment, conditions of heat or humidity during training, and often large body mass. Although athletes face this risk, athletes can maintain a state of hydration with adequate fluid intake. 64.9% of all athletes in this study were hydrated, and no athletes were found to be in a state of severe dehydration. Daily fluid intake of athletes (M=5.0 L, SD=0.9 L), which was above the AI recommendation, may have been at a level sufficient to maintain hydration. Athletes with higher urine specific gravity (USG), indicating lower level of hydration, were found to have higher levels of muscle soreness and fatigue. Increased education on hydration and more frequent monitoring of hydration status is essential to reducing risk of dehydration and its associated consequences for athlete health and performance.
- Nutritional sciences