ASSESSMENT OF SWEAT RATE AND HYDRATION STATUS IN YOUTH CROSS COUNTRY RUNNERS IN MISSISSIPPI

PURPOSE: This was an observational study aimed at assessing sweat rates and hydration status of local youth runners. Cross-country (XC) running is a sport that takes place during some of the hottest months of the year. Thus, the risk of heat-related illness is very present and is potentially higher in youth athletes due to incomplete development of their sweat response. Monitoring these athletes allows researchers and the athletic community to gain deeper understanding of youth athlete responses to heat, thus decreasing the likelihood of heat-related injury and illness. METHODS: 25 youth XC runners (age: 14.47 ± 1.46 yrs, 11 female, 14 male) participated in this study. Each runner was tested once during August or September during a school-sanctioned XC practice with coaches present. Water bottles were provided and weighed before and after practice. Every athlete was weighed in a private area without socks, shoes, or shirt. One sweat patch was then applied to each forearm of the athlete, with an elastic netting covering the patch. Immediately after practice, athletes were weighed again and patches were removed. Patches were stored in air-tight plastic tubes and wrapped in plastic wrap to decrease risk of evaporation. Samples were analyzed the day of collection. Samples were centrifuged for 10 minutes then analyzed via ion-selective electrode technology. Mean and SD were calculated, and independent sample t-tests were run to compare means between males and females. RESULTS: Average sweat rate was 1.13 ± 0.50 L/h and average sodium loss was 1290 ± 322 mg/h. Average percent body weight lost was 1 ± 1%. There was a significant difference between males and females in sweat rate (p < 0.05) and sodium loss (p = 0.016), but no difference in %BW lost (p = 0.165). CONCLUSIONS: Both sweat rate and sodium loss are greater than published youth overall norms. This is expected as these published norms are not based specifically on youth cross-country runners. Continued assessments of youth athletes will yield greater understanding of proper hydration strategies for this population. This study provided participants with individualized hydration packets to provide awareness on the importance of hydration for training and performance.