Effects of Dehydration on Motor Skills, Attention, and Performance in Adolescent Football Players

Overview

This study aims to investigate how hydration status affects attention, motor competence, and football skills in adolescent male football players aged 13-14 years. Participants will complete standardized cognitive, motor, and sport-specific tests under two conditions: normal hydration (euhydration) and controlled dehydration (hypohydration). Hydration levels will be assessed using urine colour and body mass measurements, while attention and motor skills will be evaluated with validated tools. The study seeks to understand the impact of fluid balance on physical and cognitive performance in young athletes, without altering their usual routines.

This comparative, quasi-randomised, counterbalanced, repeated-measures study investigates the effects of hydration status on cognitive function, motor competence, and football skills in adolescent male football players aged 13-14 years. A pilot study with 15 participants was conducted to determine effect size (Cohen's d = 0.43) and assess feasibility, confirming that a minimum of 73 participants would be required for the main study. Seventy-five participants met strict inclusion criteria, including voluntary participation, no chronic or metabolic diseases, and a homogeneous sporting background. Participants had a mean age of 13 ± 1 years, height of 148 ± 5 cm, weight of 42 ± 5 kg, and BMI of 19.1 ± 1.2 kg/m². Most trained 8-10 hours per week and had 3-4 years of competitive football experience. Each participant was tested under two hydration conditions: euhydration and hypohydration. In the euhydration condition, participants maintained regular fluid intake for 12 hours prior to testing and consumed 500 ml of water with a standardised breakfast. Hydration status was verified using first-morning urine samples and Armstrong's eight-point urine colour scale. In the hypohydration condition, participants underwent controlled fluid restriction and a treadmill walking protocol to achieve a 2-3% body mass loss. Pre- and post-exercise body weight and urine measurements were used to quantify hypohydration. Following each testing session, participants completed the d2 Attention Test, the Bruininks-Oseretsky Test of Motor Proficiency - Short Form (BOT-2 SF), and a structured football skill test assessing passing, dribbling, and shooting accuracy. All procedures were performed under supervision in controlled environmental conditions, with scheduled rest intervals to prevent fatigue and ensure safety. Secondary checks included urine strip tests, while perceived exertion and local muscle discomfort were monitored continuously. The study design allows for within-subject comparisons across hydration conditions to determine how fluid balance affects attention, motor skills, and sport-specific performance in adolescent athletes. Data will be analyzed to provide insights into the relationship between hydration and physical-cognitive performance in young football players, with implications for training and competition strategies.