DehydrationNCT07118904
Effect of Dehydration on Sleep Quality, Cognitive Skills, and Electromyographic Responses in Combat Athletes
A study testing Rapid weight loss through dehydration in people with Dehydration and Weight Loss, run by Abant Izzet Baysal University at 1 site in Turkey (Türkiye).
Trial 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. Read more about this study
- Who is it for?
- Ages 17 to 28 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Dehydration, Weight Loss, Weight Cycling
- What is being tested?
- Rapid weight loss through dehydration
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 12 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 18 Aug 2025to 11 Sep 2026
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 17 to 28 years
- Men only
- Healthy volunteers accepted
- Child, Adult
Who may be able to join
- Voluntary participation
- Being combat athletes with prior rapid weight loss experience
- No existing health conditions
- No orthopedic injuries
Who cannot join
- Using of sleep-related medications
- Complications During the Intervention: Participants who experience any complications during experimental intervention.
Trial locations and contacts
1 site in 1 country.
Turkey (Türkiye)1 site
Bolu Abant İzzet Baysal University, Faculty of Sport Sciences,
Bolu, 14030
About this study
Official title: 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.
Read the 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.
- Conditions
- Dehydration, Weight Loss, Weight Cycling, Sleep
- Being tested
- Rapid weight loss through dehydration
- Keywords
- Athletic Performance, Cognitive Skills, Sleep Quality, Isokinetic strength, EMG Response, Anticipation Time
- Medical subject headings
- Dehydration, Weight Loss, Weight Cycling, Sleep Initiation and Maintenance Disorders
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Rapid weight loss through dehydrationOther
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.
| Study group | Role | What they receive |
|---|---|---|
| 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. Receives: 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. Receives: 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. |
What is being measured
The primary outcome is the main question the study is designed to answer.
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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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.
Measured: 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).
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted12 Aug 2025
- Study start18 Aug 2025
- Primary completion30 Jun 2026
- Study completion11 Sep 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for DehydrationStudies of the same condition, open and under way.
- More trials run by Abant Izzet Baysal UniversityThe sponsor's other registered studies.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Randomized counterbalanced crossover design study (Two experimental trial a control trial)
- Masking
- None (open label)
- Enrolment
- 12 participants (actual)
Sponsor and investigators
- Lead sponsor
- Abant Izzet Baysal University
- Sponsor type
- University, hospital or other
- Collaborators
- The Scientific and Technological Research Council of Turkey
- Responsible party
- Principal investigator, Ümid Karlı, Abant Izzet Baysal University
- Investigators
- Umid Karli, PhD, Principal investigator, Bolu Abant İzzet Baysal University, Faculty of Sport Sciences, Department of Coaching Education
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07118904
- Sponsor's protocol ID
- BAIBU-SBF-UK-03
- Status last verified
- Mar 2026
- First submitted
- 29 Jul 2025
- Last updated
- 16 Oct 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 16 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Effect of Acute Dehydration on Sleep Quality, Cognitive Skills, and Electromyographic Responses During Maximum Contraction in Combat Athletes
- ClinicalTrials.gov ID
- NCT07118904
- Acronym / sponsor ID
- BAIBU-SBF-UK-03
- Conditions
- Dehydration, Weight Loss, Weight Cycling, Sleep
- Keywords
- Athletic Performance, Cognitive Skills, Sleep Quality, Isokinetic strength, EMG Response, Anticipation Time
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 12 participants (actual)
- Lead sponsor
- Abant Izzet Baysal UniversityUniversity, hospital or other
- Collaborators
- The Scientific and Technological Research Council of Turkey
- Study start
- 18 Aug 2025 (actual)
- Primary completion
- 30 Jun 2026 (actual)
- Study completion
- 11 Sep 2026 (actual)
- First posted
- 12 Aug 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
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.
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 design
- Primary purpose
- Treatment
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 3
- Model description
- Randomized counterbalanced crossover design study (Two experimental trial a control trial)
| Arm | Type | Receives |
|---|---|---|
| Dehydration + Dehydrated Night Trial | Experimental | Other: Rapid weight loss through dehydrationIn 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. |
| Dehydration + Rehydrated Night Trial | Experimental | Other: Rapid weight loss through dehydrationIn 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. |
| 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. |
Who may qualify
- Ages
- 17 to 28 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Child, Adult
Key inclusion criteria (4 listed)
- Voluntary participation
- Being combat athletes with prior rapid weight loss experience
- No existing health conditions
- No orthopedic injuries
Key exclusion criteria (2 listed)
- Using of sleep-related medications
- Complications During the Intervention: Participants who experience any complications during experimental intervention.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Rapid weight loss through dehydrationDehydration 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. | Other | Dehydration + Dehydrated Night Trial, Dehydration + Rehydrated Night Trial |
Primary outcome
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.
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.
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.
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.
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.
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.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 16 Oct 2026.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Umid Karli, PhD principal investigator
Bolu Abant İzzet Baysal University, Faculty of Sport Sciences, Department of Coaching Education
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Rapid weight loss through dehydration in people with Dehydration and Weight Loss, run by Abant Izzet Baysal University at 1 site in Turkey (Türkiye).
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 2 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 16 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in Turkey (Türkiye). Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
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).). The study lists 6 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 16 Oct 2026.