Assessment of hydration status of elite young male soccer players with different methods and new approach method of substitute urine strip

Background: The purpose of the study is to determine and compare the hydration status with different methods and determine fluid intake, dehydration percentages and sweat rate of 26 young male soccer players (15 +/- 1.2 years) before an important competition. More specifically, the study aims at validating the urine strip and advising the players to use it as an easy and practical method. Methods: Measurements of urine analysis were taken from the urine sample of the participants before breakfast and conducted for 3 consecutive days before the competition. Hydration status was assessed through analysis of urine color, urine specific gravity (USG) (laboratory, strip, refractometry), and osmolality. The players' dehydration percentages and sweat ratio were calculated. Results: The average values for all samples were 3 +/- 1 for color, and 1.021 +/- 4 g/cm(3) for USG (laboratory), and 1.021 +/- 3 g/cm(3) for USG (strip), and 1.021 +/- 4 for USG (refractometry), and 903 +/- 133 mOsm/kg for osmolality. USG (strip) was highly correlated with USG (laboratory), USG (refractometry) (r = 0.8; P < 0.01) and osmolality (r = 0.7; P < 0.01), and moderately correlated with urine color (r = 0.4; P < 0.05). The mean dehydration percentage and sweat rate of the soccer players were observed as 0.5 % and 582.3 +/- 232.0 mL/h, respectively. Conclusion: We found that youth soccer players are under a slight risk of dehydration under moderate weather conditions. As indicated by the research results, determination of hydration status of athletes must be taken into account more carefully under moderate and hot weather conditions. In addition, hydration methods were compatible with one another as measured in this study.