Maintaining proper hydration is a challenge for athletes. Dehydration can result in decreased athletic performance and potentially life-threatening complications. While the dangers of dehydration are well known, there is no literature investigating how training load and the environment affect hydration status during multiple bouts of soccer training. Therefore, Sekiguchi and colleagues investigated how training load and the environmental conditions relate to hydration status during a collegiate pre-season. Twenty-eight NCAA Division 1 male soccer players participated in this 19-day study. Prior to each training session, the body mass, urine specific gravity, and urine color of all participants were recorded and each participant consumed 500 mL of water. Participants wore a heart rate monitor and GPS-based tracker to track session-time, total distance, total distance per session, average heart rate, average speed, and training load score (individualized score accounting for a person’s activity and fitness). Researchers also considered the ambient temperature and relative humidity, which the nearest local weather station collected. During training, all participants had unlimited access to water, and water intake during this time was not recorded. Following any bout of training, participants consumed another 500 mL of water and body mass was assessed to determine change that occurred during training. The typical temperature during a session ranged from 20 to 28°C with relative humidity between 53 to 89%. The percent body mass loss never exceeded 2% during a session. On average, participants arrived at more than 80% of training sessions hypohydrated based on urine specific gravity, urine color, or both. The total distance during training was the most important factor associated with percent body mass loss. Relative humidity and ambient temperature only contributed a little bit to estimating the percent body mass loss.
Factors influencing hydration status during a National Collegiate Athletics Association division 1 soccer preseason.
Sekiguchi Y, Adams WM, Curtis RM, Benjamin CL, Casa DJ. J Sci Med Sport. 2018. [Epub Ahead of Print].
Take Home Message: Participants engaging in pre-season soccer training were hypohydrated during at least 80% of training sessions. An athlete who traveled a greater distance during training was more likely to experience a greater loss in body mass during training.
The researchers present new real-world evidence that total distance during a session of preseason collegiate soccer relates to change in hydration. Ideally, these results should influence coaches and medical staff to encourage hydration and provide more hydration breaks when players have greater distances during a session. This will reduce hydration deficits and positively influence performance. Clinicians should always be cautious about how we apply results from one study to other athletes. These authors focused on a small group of male soccer players at a single institution where the temperatures tend to be below 83°F and the percent body mass loss was less than 2% per session. Future researchers should continue this line of studies to understand the role training load has on hydration status and seek to understand how geography/climate, sex, and sport have during this critical training period. In the meantime, clinicians should be cautious and recognize that an athlete who covers a greater distance during a training session may be more likely to lose more fluids. Hence, a clinician should consider extra steps for this athlete to promote healthy hydration.
Questions for Discussion: What factors do you assess to help prevent hypohydration? Would the factors in this current study be something you would consider recording? Why or why not?
Reviewed by: Jeffrey Driban
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