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

March 12, 2026 updated by: Abant Izzet Baysal University

The Effect of Acute Dehydration on Sleep Quality, Cognitive Skills, and Electromyographic Responses During Maximum Contraction in Combat Athletes

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.

Study Overview

Status

Recruiting

Conditions

Intervention / Treatment

Detailed Description

The objective of this study is to examine the impact of rapid weight loss through dehydration on sleep quality, cognitive skills, and surface electromyographic (sEMG) responses during isokinetic strength performance in combat athletes. Additionally, the overall effect of acute dehydration and the potential adverse effects of dehydration on sleep quality on cognitive abilities, and sEMG responses will be evaluated. Body temperature and heart rate values will be monitored throughout the study. Finally, the effect of rehydration on cognitive skills, strength, and sEMG responses after a night of dehydration will be evaluated.

Competitive senior male combat athletes will participate in this study. The first stage will involve the determination of urine density, the recording of body weight, the measurement of body composition and total body fluid, and the recording of resting heart rate (HR) and body temperature. Subsequently, cognitive skill tests will be administered, and following a standard warm-up, sEMG data will be recorded from the dominant leg quadriceps muscle region during isokinetic leg strength measurements.

Following the completion of the pre-tests, each athlete will be subjected to two separate dehydration and control applications in accordance with the randomised crossover experimental design. In the experimental trials, 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 in experimental trial 1 will be permitted to engage in a routine night without rehydration. During this period, their sleep quality will be recorded with a sleep monitor. 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. In the experimental trial 2, they 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. In the control trial, all tests in the experimental trials will be performed without body weight loss due to dehydration. All participants will be randomly assigned to the dehydration and control trials, with each athlete participating in the respective trial at one-week intervals.

Study Type

Interventional

Enrollment (Estimated)

12

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact Backup

Study Locations

  • Turkey (Türkiye)
      • Bolu, Turkey (Türkiye), 14030
        • Recruiting
        • Bolu Abant İzzet Baysal University, Faculty of Sport Sciences,
        • Contact:
        • Sub-Investigator:
          • Semih Karaman, Ms
        • Sub-Investigator:
          • Koray Gökmen, Ms
        • Principal Investigator:
          • Umid Karlı, Phd

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Child
  • Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

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

Exclusion Criteria:

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

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Dehydration + Dehydrated Night Trial

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 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.
Experimental: Dehydration + Rehydrated Night Trial
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
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.
No Intervention: Control Trial
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.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Sleep monitoring and Evaluation
Time Frame: 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).
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
Time Frame: 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).
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
Time Frame: 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).
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
Time Frame: 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).
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
Time Frame: 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).
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
Time Frame: 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).
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).

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Abant Izzet Baysal University

Collaborators

The Scientific and Technological Research Council of Turkey

Investigators

  • Principal Investigator: Umid Karli, PhD, Bolu Abant İzzet Baysal University, Faculty of Sport Sciences, Department of Coaching Education

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

August 18, 2025

Primary Completion (Estimated)

May 28, 2026

Study Completion (Estimated)

August 30, 2026

Study Registration Dates

First Submitted

July 29, 2025

First Submitted That Met QC Criteria

August 5, 2025

First Posted (Actual)

August 12, 2025

Study Record Updates

Last Update Posted (Actual)

March 16, 2026

Last Update Submitted That Met QC Criteria

March 12, 2026

Last Verified

March 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • BAIBU-SBF-UK-03

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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