Effect of Dehydration on Sleep Quality, Cognitive Skills, and Electromyographic Responses in Combat Athletes

NCT07118904 | Recruiting

• 1 other identifier: BAIBU-SBF-UK-03
• Study Type: interventional
• Target: 12
• Locations: 1 country
• Sites: 1

Brief Summary

This study examines the effects of rapid dehydration-induced weight loss on combat athletes' sleep quality, cognitive skills, and isokinetic strength performance. The research documents both benefits and risks of weight-cutting practices for athletes, coaches, and medical staff in weight-class sports. Findings will guide safer weight management approaches and inform potential revisions to international weigh-in protocols, while contributing valuable insights to sports science.

Conditions

Dehydration; Weight Loss; Weight Cycling; Sleep

Keywords

Athletic Performance; Cognitive Skills; Sleep Quality; Isokinetic strength; EMG Response; Anticipation Time

Outcome Measures

Primary Outcomes (6)

• Sleep monitoring and Evaluation

  Participants' sleep assessments will be conducted with a sleep monitor, which uses impulse radio ultra-wide band (IR-UWB) radar and Doppler technology, and has been shown to provide measurements as accurate and reliable as the polysomnography device, which is considered the gold standard in sleep assessment. Total sleep and wake times and durations of the sleep phases will be obtained in minutes from the recordings of the device.

  First trial monitoring, following one week Second trial monitoring and following one week Third trial monitoring (Due to randomized counterbalanced crossover design, monitoring will be performed three times, two as experimental and one as control).

• Isokinetic Leg Strength Measurement

  Isokinetic leg strength measurements will be made with the Cybex Norm device. Peak torque data obtained during the measurements will be recorded and used in data processing.

  First trial testing, following one week Second trial testing and following one week Third trial testing (Due to randomized counterbalanced crossover design, testing will be performed three times, two as experimental and one as control).

• EMG Measurements

  Electrical potentials of muscle cells are recorded with electromyography (EMG) and the activities of skeletal muscles are evaluated based on changes in these potentials. EMG measurement provides information about the muscles and motor nerves involved by analyzing motor unit action potentials.

  First trial testing, following one week Second trial testing and following one week Third trial testing (Due to randomized counterbalanced crossover design, testing will be performed three times, two as experimental and one as control).

• Stroop test

  The Stroop test is a test that reflects frontal lobe region activity.

  First trial testing, following one week Second trial testing and following one week Third trial testing (Due to randomized counterbalanced crossover design, testing will be performed three times, two as experimental and one as control).

• Symbol Digit Modalities Test

  The Symbol Digit Modalities Test is a test that evaluates complex visual spatial scanning, sustained attention and concentration, information processing speed and working memory.

  First trial testing, following one week Second trial testing and following one week Third trial testing (Due to randomized counterbalanced crossover design, testing will be performed three times, two as experimental and one as control).

• Montreal Cognitive Assessment

  The Montreal Cognitive Assessment test evaluates cognitive functions such as attention and concentration, executive functions, memory, language, visual construction skills, calculation and orientation. The test scores range from 0 to 30, with a cut-off score of 21. Scores of 21 and above are considered normal.

  First trial testing, following one week Second trial testing and following one week Third trial testing (Due to randomized counterbalanced crossover design, testing will be performed three times, two as experimental and one as control).

Study Arms (3)

Dehydration + Dehydrated Night Trial

EXPERIMENTAL

In this trial 3% weight loss will be achieved with sauna application by taking the body weights recorded in the pre-test as a reference. Following the dehydration application, all measurements taken in the pre-test before the application will be repeated in order after approximately 45 minutes. Athletes will be permitted to engage in a routine night without rehydration. During this period, their sleep quality will be recorded with a sleep tracker. The next day in the morning, all measurements taken in the pre-test will be repeated in order to evaluate the effect of dehydration and the possible negative effect of dehydration on sleep quality on the dependent variables. Following the completion of the morning measurements, the athletes will be permitted to consume fluids and food within two hours in order to reach their body weights in the pre-test. All tests will be reapplied for the last time to the athletes who have reached the state of rehydration, respectively.

Other: Rapid weight loss through dehydration

Dehydration + Rehydrated Night Trial

EXPERIMENTAL

In this trial 3% weight loss will be achieved with sauna application by taking the body weights recorded in the pre-test as a reference. Following the dehydration application, all measurements taken in the pre-test before the application will be repeated in order after approximately 45 minutes, with the athlete refraining from consuming any food or liquid. Athletes will be permitted to rehydrate after the second measurements and will be asked to spend a routine night. The remaining tests will be repeated in accordance with the experimental trial 1 protocol.

Other: Rapid weight loss through dehydration

Control Trial

NO INTERVENTION

No intervention will be conducted. All tests to be used to measure dependent variables will be conducted in accordance with the Experimental trial 1 protocol.

Interventions

Rapid weight loss through dehydration OTHER

Dehydration will be induced by exposing athletes to sauna heat with an average temperature of 70-80°C. The participants will undergo consecutive 15 minute sessions in sauna with 5 minute breaks until 3% weight loss is achieved. No liquids or food will be consumed between sessions.

Dehydration + Dehydrated Night Trial; Dehydration + Rehydrated Night Trial

Eligibility Criteria

• Age: 17 Years - 28 Years
• Gender Eligibility Details: Male individuals will be included due to the fact that women's hormonal responses may cause heterogeneous findings and the difficulty in interpreting the findings due to their hormonal profile.
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64)

You may qualify if:

• Voluntary participation
• Being combat athletes with prior rapid weight loss experience
• No existing health conditions
• No orthopedic injuries

You may not qualify if:

• Using of sleep-related medications
• Complications During the Intervention: Participants who experience any complications during experimental intervention.

Sponsors & Collaborators

• Abant Izzet Baysal University: lead
• The Scientific and Technological Research Council of Turkey: collaborator

Study Sites (1)

Bolu Abant İzzet Baysal University, Faculty of Sport Sciences,

Bolu, 14030, Turkey (Türkiye)

RECRUITING

MeSH Terms

Conditions

Dehydration; Weight Loss; Weight Cycling; Sleep Initiation and Maintenance Disorders

Condition Hierarchy (Ancestors)

Water-Electrolyte Imbalance; Metabolic Diseases; Nutritional and Metabolic Diseases; Pathologic Processes; Pathological Conditions, Signs and Symptoms; Body Weight Changes; Body Weight; Signs and Symptoms; Weight Gain; Sleep Disorders, Intrinsic; Dyssomnias; Sleep Wake Disorders; Nervous System Diseases; Mental Disorders

Study Officials

• Umid Karli, PhD

  Bolu Abant İzzet Baysal University, Faculty of Sport Sciences, Department of Coaching Education

  PRINCIPAL INVESTIGATOR

Central Study Contacts

Umid Karli, PhD

CONTACT

+90 374 254 10 00; karli_u@ibu.edu.tr

Kutlu Aydın, PhD

CONTACT

+90374 254 10 00; aydin_k@ibu.edu.tr

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: NONE
• Purpose: TREATMENT
• Intervention Model: CROSSOVER
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Randomized counterbalanced crossover design study (Two experimental trial a control trial)

Study Record Dates

• First Submitted: July 29, 2025
• First Posted: August 12, 2025
• Study Start: August 18, 2025
• Primary Completion (Estimated): May 28, 2026
• Study Completion (Estimated): August 30, 2026
• Last Updated: March 16, 2026

Record last verified: 2026-03

Locations

TU (1)