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

NCT07320313 | Completed

• 1 other identifier: 548-548-10
• Study Type: interventional
• Target: 75
• Locations: 1 country
• Sites: 1

Brief Summary

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.

Conditions

Hydration Status; Sport Performance; Football; Adolescent Athletic Performance; Cognitive Function and Well-Being

Keywords

Hypohydration; Adolescents; Football; Motor Competence; Attention; Technical Skills

Outcome Measures

Primary Outcomes (4)

• Body Mass Index (BMI)

  Body mass index (BMI) was calculated using height and body weight measurements obtained at baseline. Height was measured once at baseline using a standard stadiometer, and body weight was measured immediately prior to any exercise or fluid manipulation using a calibrated scale with ±50 g precision (InBody 120). BMI was calculated as body weight (kg) divided by height squared (m²).

  Baseline (single assessment during one laboratory visit prior to any exercise or hydration manipulation)

• Hydration status assessed using urine color

  Hydration status was assessed using first-morning urine samples (50-60 mL) collected prior to exercise and immediately following the exercise-induced dehydration protocol. Urine samples were analyzed using Armstrong's eight-point urine color chart. Urine color values of 1-2 indicated euhydration, whereas values of 5-6 indicated moderate hypohydration.

  Baseline (first-morning urine sample) and immediately post-exercise (within 5 minutes after completion of treadmill exercise), assessed during a single test day

• Hydration Status via Body Mass Loss

  Exercise-induced body mass loss was used as an objective indicator of hydration status. Body weight was measured immediately before exercise and again within 5 minutes after completion of the treadmill protocol. Percentage hypohydration was calculated as the percentage change in body mass relative to baseline body weight. A body mass loss of 2-3% was considered indicative of significant hypohydration.

  Baseline (pre-exercise body weight) and immediately post-exercise (within 5 minutes after completion of treadmill exercise), assessed during a single laboratory visit

• Perceived Exertion and Muscle Discomfort

  Perceived exertion was assessed using Borg's 6-20 Rating of Perceived Exertion (RPE) scale, and localized muscle discomfort was monitored through direct observation, particularly in the lower limbs. Ratings were recorded at regular 10-minute intervals during the treadmill protocol to ensure participant safety and to monitor subjective fatigue.

  From start of treadmill exercise until completion of the exercise protocol (up to 60 minutes), assessed during a single laboratory visit

Secondary Outcomes (3)

• d2 Attention Test

  Post-exercise recovery period, assessed once between 8 and 15 minutes after completion of treadmill exercise during a single test day

• Bruininks-Oseretsky Test of Motor Proficiency - Short Form (BOT-2 SF)

  Post-exercise recovery period, assessed once between 15 and 30 minutes after completion of treadmill exercise during a single test day

• Football Skill Test

  Post-exercise recovery period, assessed once between 30 and 45 minutes after completion of treadmill exercise during a single test day

Study Arms (2)

Euhydration Condition

EXPERIMENTAL

Participants completed the euhydration condition first. They maintained habitual fluid intake for approximately 12 hours prior to testing, consuming 1.5-2.0 litres of water ad libitum during the day and night. On the morning of testing, a standardized breakfast was consumed along with 500 ml of water approximately two hours before testing. Participants were instructed not to urinate during the final 30 minutes prior to the session. Hydration status was verified using first-morning urine samples assessed via Armstrong's eight-point urine colour chart (target 1-2) and pre-test body mass measurements. Once classified as adequately hydrated, participants completed the d2 Attention Test, the Bruininks-Oseretsky Test of Motor Proficiency - Short Form (BOT-2 SF), and a structured football skill test. Attention and motor tests were conducted indoors, followed by the football skill test on an outdoor pitch. All testing was performed under supervision, with small participant groups to ensure st

Behavioral: Euhydration Protocol

Hypohydration Condition

EXPERIMENTAL

After completing the euhydration condition and following a minimum 48-hour washout period, the same participants completed the hypohydration condition. Fluid intake was restricted beginning at 17:00 the day before testing, with no fluids overnight, and a low-fluid breakfast was provided on the morning of the session. Hypohydration was induced via a controlled treadmill walking protocol, with speed and duration individually adjusted to achieve 2-3% body mass loss. Participants were continuously monitored for heart rate, perceived exertion (Borg 6-20 scale), and localized muscle discomfort. Body mass was measured every 10 minutes, and fluid intake was not permitted during exercise. Hydration status was confirmed via pre- and post-exercise urine colour and body mass measurements, with urine strip tests as a secondary check. After a 15-minute seated recovery and consumption of low-water snacks, participants repeated the d2 Attention Test, BOT-2 SF, and football skill test under hypohydrat

Behavioral: Hypohydration Protocol

Interventions

Euhydration Protocol BEHAVIORAL

Participants maintained their habitual fluid intake for 12 hours prior to testing, approximately 1.5-2.0 L ad libitum throughout the day and night, and consumed 500 mL of water with a standardized breakfast approximately two hours before the test. Participants were instructed to refrain from urinating during the 30 minutes preceding testing. Hydration status was verified using first-morning urine colour assessed on Armstrong's 8-point scale (target range 1-2) and pre-test body mass measurements. Cognitive, motor, and football skill performance were subsequently evaluated under these euhydrated conditions using the d2 Attention Test, BOT-2 SF, and a structured football skill test, respectively.

Also known as: Hydration Maintenance Protocol, Normal Hydration Condition

Euhydration Condition

Hypohydration Protocol BEHAVIORAL

Participants underwent a hypohydration protocol beginning with fluid restriction from 17:00 on the day prior to testing, with no fluid consumption overnight, and a low-fluid breakfast on the morning of the session. Hypohydration was induced via supervised treadmill walking for approximately 45 ± 5 minutes at \~5.5 km/h with a 5% incline under moderate environmental conditions. No fluids were allowed during exercise, and body mass was measured every 10 minutes. Treadmill duration and intensity were individually adjusted until participants achieved a target body mass loss of 2-3%. Hydration status was confirmed via pre- and post-exercise urine colour and body mass measurements, with urine strip tests applied as a secondary verification. Following a 15-minute seated recovery period with consumption of low-water snacks, participants completed the d2 Attention Test, BOT-2 SF, and football skill test under hypohydrated conditions. Safety was continuously monitored via heart rate, Borg RPE sca

Also known as: Fluid Restriction + Exercise-Induced Dehydration Protocol

Hypohydration Condition

Eligibility Criteria

• Age: 13 Years - 14 Years
• Gender Eligibility Details: The study includes only male participants. This restriction is due to the potential confounding effects of female sex hormones and the menstrual cycle. Estrogen and progesterone fluctuations across the menstrual cycle can influence fluid balance, thermoregulation, and exercise performance. To minimize hormonal variability and ensure more controlled evaluation of hydration-related outcomes, only males were included.
• Healthy Volunteers: Yes
• Age Groups: Child (0-17)

You may qualify if:

• Male sex (to avoid hormonal variability related to the menstrual cycle)
• Voluntary participation
• Age between 13 and 14 years
• Similar sporting background (regular football training and competition experience)
• No chronic or metabolic disease
• No respiratory or renal disease
• No medical condition requiring fluid restriction
• Not taking any medications or dietary supplements (e.g., vitamins, minerals, creatine, protein)
• No recent history of injury

You may not qualify if:

• Outside the specified age range
• Female sex
• Diagnosis of chronic/metabolic, respiratory, or renal disease
• Regular use of medication, diuretics, or dietary supplements (e.g., vitamins, - minerals, creatine, protein)
• Medical condition requiring fluid intake restriction
• Not engaged in sports or without a football background
• Recent injury history

Sponsors & Collaborators

• bekir tokay: lead
• Uşak University: collaborator

Study Sites (1)

Faculty of Sports Sciences

Uşak, Uşak, 64200, Turkey (Türkiye)

Location

Study Officials

• Mustafa AKIL, Professor Doctor

  Uşak University, Department of Sports Science

  STUDY CHAIR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: BASIC SCIENCE
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR INVESTIGATOR
• PI Title: Instructor, Ph.D

Model Details: This is a randomized crossover trial in which all participants undergo both the euhydration and hypohydration conditions. The order of the conditions is counterbalanced to minimize order effects, and each participant serves as their own control.

Study Record Dates

• First Submitted: September 21, 2025
• First Posted: January 6, 2026
• Study Start: January 23, 2025
• Primary Completion: January 23, 2025
• Study Completion: April 30, 2025
• Last Updated: January 6, 2026

Record last verified: 2025-12

Locations

TU (1)