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Effects of Hydration Changes on Neuromuscular Function of Athletes (H2OAthletes)

The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been evaluated by the U.S. Federal Government. Know the risks and potential benefits of clinical studies and talk to your health care provider before participating. Read our disclaimer for details.
 
ClinicalTrials.gov Identifier: NCT05380089
Recruitment Status : Recruiting
First Posted : May 18, 2022
Last Update Posted : May 29, 2024
Sponsor:
Information provided by (Responsible Party):
Faculdade de Motricidade Humana

Brief Summary:

Greater muscular strength and power are relevant qualities for athletic success and decreased injury rate. It is known that dehydration impairs muscular strength and power, although the explanation for this association is not entirely clear. Besides morphological factors, strength production also depends on neural factors which in turn can be affected by dehydration. Some studies tested the effects of dehydration on neuromuscular function using electromyography (EMG) analysis. However, there is no consensus among those studies.

Additionally, exercise may disturb water balance. This can further lead to dehydration if the athlete does not properly rehydrate. In this sense, the scientific evidence has identified people who are considered low drinkers that may be more susceptible to cellular shrinkage, potentially impairing health and performance. Thus, it would be expected that athletes regularly exposed to lower amounts of water intake would have beneficial effects in both performance and health if higher water ingestion was promoted, namely an improved neuromuscular function via enhanced cellular hydration. However, any potential benefit of increasing water intake on neuromuscular function is still to be determined using well-designed experimental studies and state-of-the-art methods.

Lastly, there is no consensus regarding the diagnosis of dehydration in athletes. The identification of simple indices to measure dehydration in athletes is crucial as many may be inaccurately diagnosed.


Condition or disease Intervention/treatment Phase
Dehydration Hyperhydration Other: Increasing water intake Not Applicable

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Study Type : Interventional  (Clinical Trial)
Estimated Enrollment : 50 participants
Allocation: Randomized
Intervention Model: Parallel Assignment
Intervention Model Description: A randomized controlled trial (RCT)
Masking: None (Open Label)
Masking Description: Given the nature of the study, it is not possible to blind neither participants nor research team members regarding the allocated groups.
Primary Purpose: Basic Science
Official Title: Effects of Hydration Changes on Neuromuscular Function of Athletes With Low Water Intake
Actual Study Start Date : November 1, 2021
Estimated Primary Completion Date : October 31, 2024
Estimated Study Completion Date : December 31, 2024

Resource links provided by the National Library of Medicine


Arm Intervention/treatment
Experimental: Experimental group

Over a 4-day period, participants randomly assigned to the experimental group will be instructed to maintain normal solid food choices, but to increase water intake to achieve a total water intake of ≥45ml/kg/day. Prepared bottles of water with the required amount will be given to each participant every morning and collected empty the following day. Instructions to drink small amounts of water every hour be transmitted.

Adherence to instructions regarding water intake will be determined by the return of drinking bottles, analysis of daily food records, assessment of water flux (i.e., collecting urines after subjects being dosed with deuterium), and daily screening questions. These samples will be delivered on a subsequent morning during a daily laboratory visit to collect urine and saliva samples, as well as BI assessment. On the 4th day, participants will perform a neuromuscular function assessment.

Other: Increasing water intake
Participants randomly assigned to the experimental group will be instructed to maintain habitual solid food choices and to increase water intake to achieve a total water intake of ≥45ml/kg/day.

No Intervention: Control group
Participants randomly assigned to the control group will be instructed to maintain normal solid food choices and water intake based on their average intake reported on the food records. Adherence to instructions regarding water intake will be determined and assessments performed will occur as mentioned previously for the experimental group.



Primary Outcome Measures :
  1. Maximum voluntary isometric contraction - Knee extension [ Time Frame: 3 weeks ]

    For the lower body strength, participants will be assessed on a Biodex System 3 Pro isokinetic dynamometer (Biodex Medical Systems, Shirley, NY). The participants will remain seated with the belts positioned on the thorax, abdomen, thigh, and above the knee on the side that is being evaluated to limit the knee movement.

    Each testing session will begin with a dynamic warm-up, consisting of 5min of submaximal cycle-ergometry set at 25 W followed by a 5 min of resting before starting the testing protocol. First, a MVIC 5-s voluntary knee extension (knee at 70o for the extension). Verbal encouragement and audible feedback from the dynamometer software will be provided to each participant.


  2. Maximum voluntary isometric contraction - Knee flexion [ Time Frame: 3 weeks ]
    After the maximum voluntary isometric contraction for knee extension, participants will be asked to perform a MVIC 5-s voluntary knee flexion (30o for the flexion). This test will be performed with 3min of pause after the MVIC of knee extension.

  3. Rate of torque development (RTD) for knee extension and flexion [ Time Frame: 3 weeks ]
    In both MVIC for knee extension and flexion, the participants will be instructed to avoid any countermovement prior to test and will be asked to exert their maximum force as fast and hard as possible, to obtain both maximal torque and rate of torque development (RTD). Verbal encouragement and audible feedback from the dynamometer software will be provided to each participant.

  4. 5 submaximal isometric repetitions of knee extension [ Time Frame: 3 weeks ]
    5 submaximal isometric repetitions will me measuredfrom MVIC of baseline and MVIC of that day: 1) 30s at 20% of MVIC; 2) 30s at 40% of MVIC; 3) 10s at 60% of MVIC; 4) 10s at 80% of MVIC; 5) 10s at 100% of MVIC. Between repetitions a pause of 1 min will be performed between repetitions while a pause of 3 min will be performed between sets.

  5. Fatigue task [ Time Frame: 3 weeks ]
    Last, and after a pause of 5 min, participants will perform an isometric contraction at 40% of MVIC (measured on the day) until to exhaustion. Exhaustion will be considered if a decrease of more than 10% of MVIC for more than 10s is observed.

  6. EMG signals - Root mean square [ Time Frame: 3 weeks ]
    During the legs' strength assessment, EMG signals will be recorded (EMG Delsys Trigno Avanti, Delsys Incorporated, USA) from the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), and biceps femoris (BF) muscles in accordance with the guidelines of the Surface EMG for the Non-invasive Assessment of Muscles (SENIAM). The electrodes will be placed before the 5 min of resting after the dynamic warm-up. EMG signals from each muscle will be pre-amplified (gain 1000), band-pass filtered (20-450 Hz), and A/D converted at 1kHz (MP100, BIOPAC Systems Inc., Goleta, CA). AcqKnowledge 4.3.1 software will be used for data collection and processing (BIOPAC Systems Inc., Goleta, CA).

  7. EMG signals - Mean power frequency [ Time Frame: 3 weeks ]
    During the legs' strength assessment, EMG signals will be recorded (EMG Delsys Trigno Avanti, Delsys Incorporated, USA) from the vastus lateralis (VL), rectus femoris (RF), vastus medialis (VM), and biceps femoris (BF) muscles in accordance with the guidelines of the Surface EMG for the Non-invasive Assessment of Muscles (SENIAM). The electrodes will be placed before the 5 min of resting after the dynamic warm-up. EMG signals from each muscle will be pre-amplified (gain 1000), band-pass filtered (20-450 Hz), and A/D converted at 1kHz (MP100, BIOPAC Systems Inc., Goleta, CA). AcqKnowledge 4.3.1 software will be used for data collection and processing (BIOPAC Systems Inc., Goleta, CA).

  8. Handgrip strength [ Time Frame: 3 weeks ]
    The handgrip strength test measures maximum voluntary isometric contraction (MVIC) of the hand and forearm muscles. Handgrip will be performed using a portable hand dynamometer (TSD121C; Biopac Systems, Goleta, CA, USA). Participants will be assessed on both hands alternately, in a standing position. Prior to the test, the grip dynamometer will be adjusted to the size of the hand of each subject. Handgrip strength assessment will be conducted with the subject standing up with the arms in a neutral position (halfway between supine and pronation position). Each participant will be assessed on both hands alternately until reaching 3 attempts for each hand. In each attempt, the subject will exert the maximal grip strength on the handgrip dynamometer with the assessed hand for 5s. After each attempt, there will be a resting period of 60s that will be used both for recovery and for changing the handgrip dynamometer to the opposite hand.


Secondary Outcome Measures :
  1. Food records [ Time Frame: 3 weeks ]
    A trained dietitian will calculate the athlete's habitual total water intake (i.e., the sum of the water present in beverages and the water in foods) based on a 3 non-consecutive days food record. Before filling the food records, a registered dietitian will provide written instructions using specific guidelines, pictures of portion sizes, and examples of common errors in recording dietary intake. The Portuguese Food guide will be used for the estimation of ingested portions. For the conversion of the contribution of water from food, the software package Food Processor Plus® (ESHA Research, USA) will be used by a registered dietitian.

  2. Cardiorespiratory Fitness Test [ Time Frame: 3 weeks ]

    A trained exercise physiologist will perform a maximal cardiorespiratory fitness test using an incremental test on variable speed and incline treadmill (Pulsar 3p, HP Cosmos, Nussdorf-Traunstein, Germany).The participants will perform the incremental test until exhaustion to determine their VO2max and the VT. The test will start with a 5-min seated period followed by a 1-min warm-up at 8kmh-1 with consecutive increases of 1kmh-1 per minute until exhaustion. Recovery consisted of a 3 min walk at 2.4kmh-1 speed and a grade of 2.5%.

    Expired gas measurements will be taken using a breath-by-breath metabolic cart (QUARK RMR, version 9.1, Cosmed, Rome, Italy). The VO2 and heart rate data, obtained throughout the graded exercise test, will be displayed in 20-s averages. The highest VO2 attained at the end of the test will be accepted as VO2max if a plateau in VO2 with an increase in treadmill speed was observed.


  3. Plasma osmolality [ Time Frame: 3 weeks ]
    Plasma osmolality (mOsm/kg) will be assessed by using the osmometer (Mod OSMO1, Advanced Instruments, Canada). Blood samples will be drawn from an antecubital vein via single venepuncture and will be collected in serum and plasma EDTA tubes. All blood samples will be centrifuged at 5000 rpm for 15 min at -4°C. Serum osmolality will be measured immediately following centrifugation.

  4. Urine osmolality [ Time Frame: 3 weeks ]

    Urine osmolality (mOsm/kg) will be assessed by using the osmometer (Mod OSMO1, Advanced Instruments, Canada). Urine osmolality (Uosm) is a measure of the number of dissolved particles per unit of water in urine. The osmolality of the urine sample reflects the self-regulating activity of renal concentration or dilution mechanisms during a 24-h period. Participants will receive a container for collecting and storing their urine.

    Blood samples will be drawn from an antecubital vein via single venepuncture and will be collected in serum and plasma EDTA tubes. All blood samples will be centrifuged at 5000 rpm for 15 min at -4°C. Serum osmolality will be measured immediately following centrifugation.


  5. Saliva osmolality [ Time Frame: 3 weeks ]
    Saliva (mOsm/kg) will be assessed by using the osmometer (Mod OSMO1, Advanced Instruments, Canada). For saliva sample collection, subjects then will provide unstimulated saliva by sitting quietly for 2min, allowing saliva to passively accumulate in the mouth. Then, participants will hold a salivette and remove its stopper. They will remove the swab from sallivete by tipping the container, so the swab falls directly into the mouth. To collect saliva, they will roll the swab in their mouth until they feel that they can no longer prevent their selves from swallowing the saliva produced. They will be instructed to not touch the swab with fingers during this process.

  6. Thirst and mouth dryness [ Time Frame: 3 weeks ]
    visual analogue rating scales of thirst and mouth dryness will be obtained. Participants will answer two questions by placing a mark on a 10 cm line according to their subjective analyses. The ends of the thirst line represent "Not at all thirsty" and "I'm very thirsty" and the question is "How thirsty do you feel now?". For mouth dryness the question is "How dry does your mouth feel now?" and the participants will mark the line between these ends representing "Not at all dry" and "Very dry".

  7. Serum arginine vasopressin [ Time Frame: 3 weeks ]
    Blood samples will be collected to assess serum AVP through ELISA.

  8. Serum sodium concentration [ Time Frame: 3 weeks ]
    Blood samples will be collected to assess serum sodium concentration by flame spectrometry

  9. Total body water [ Time Frame: 3 weeks ]
    Total body water (TBW) will be measured by deuterium dilution using a Hydra stable isotope ratio mass spectrometer (PDZ, Europa Scientific, UK). After a 12h fast, the first urine sample will be collected. Each participant will take an oral dose of 0.1g of 99.9% 2H2O per kg of body weight (Sigma-Aldrich;St. Louis, MO). After a 4h equilibration period, during which no food or beverage will be consumed, a urine sample will be collected as well as a urine sample at 5h. Urine and diluted dose samples will be prepared for 1H/2H analysis.

  10. Extracellular water [ Time Frame: 3 weeks ]
    Through the dilution of sodium bromide (NaBr), it will be possible the determination of ECW. After collection of a saliva sample, each participant will be asked to drink 0.030g of 99.0% NaBr (Sigma-Aldrich; St. Louis, MO) per kg of body weight, diluted in 50 mL of distilled deionized water. After a 3h equilibration period, during which no food or beverage will be consumed, a saliva sample will be collected. Saliva samples will be collected into salivettes. Then, the samples will be centrifuged and frozen for posterior analyses.

  11. Intracellular water [ Time Frame: 3 weeks ]
    Intracellular water (ICW) will be determined as the difference between TBW and ECW using the dilution techniques (ICW=TBW-ECW).

  12. Phase angle [ Time Frame: 3 weeks ]
    Whole body and segmental BI will be applied using the AKERN BIA 101/BIVA PRO, a phase-sensitive a single frequency bioelectrical impedance analysis (BIA) device that measures PhA.

  13. Impedance [ Time Frame: 3 weeks ]
    Whole body and segmental BI will be applied using the AKERN BIA 101/BIVA PRO, a phase-sensitive a single frequency bioelectrical impedance analysis (BIA) device that measures impedance (Z)

  14. Resistance [ Time Frame: 3 weeks ]
    Whole body and segmental BI will be applied using the AKERN BIA 101/BIVA PRO, a phase-sensitive a single frequency bioelectrical impedance analysis (BIA) device that measures PhA and impedance (Z), and then calculates resistance.

  15. Reactance [ Time Frame: 3 weeks ]
    Whole body and segmental BI will be applied using the AKERN BIA 101/BIVA PRO, a phase-sensitive a single frequency bioelectrical impedance analysis (BIA) device that measures PhA and impedance (Z), and then calculates reactance.

  16. Classic Bioimpedance Vector Analysis (BIVA) [ Time Frame: 3 weeks ]
    Classic BIVA will be performed, i.e., normalizing R and Xc parameters for stature (H) in meters. The length of the vector will be calculated as the hypotenuses of individual impedance values. The PhA will be calculated as the arc-tangent of Xc/R × 180°/π. Prior to each test, the analyser will be checked for calibration.

  17. Fat mass [ Time Frame: 3 weeks ]

    Fat mass (FM), a molecular component, is calculated from mathematical models, a reference 4-compartment model, as described below:

    FM (kg) = 2.748×BV - 0.699×TBW + 1.129×Mo - 2.051×BW, where BV is body volume (L) obtained by air displacement plethysmography (ADP, described below), TBW (kg) through dilution techniques (as described before), Mo is bone mineral (kg) obtained by dual-energy X-ray absorptiometry (DXA, described below), and BW is body weight (kg). Accordingly, FFM is calculated as FM minus BW. In this model soft minerals (Ms), a small molecular component, are calculated as 0.00129*TBW.


  18. Body volume [ Time Frame: 3 weeks ]
    Body volume will be assessed by ADP (BOD PODs, Life Measurement Inc., Concord, CA, USA). Each subject will wear a swimsuit and their body mass will be measured to the nearest 100g by an electronic scale connected to the plethysmograph computer. Body volume will be computed based on the initial BV corrected for thoracic gas volume and a surface area artifact computed automatically. The measured thoracic gas volume will be obtained in all subjects.

  19. Bone mineral content [ Time Frame: 3 weeks ]
    Bone mineral content will be estimated using DXA (Hologic Explorer-W, MA, USA). The attenuation of X-rays pulse between 70 and 140kV synchronously with the line frequency for each pixel of the scanned image. The lab technician will execute the analyses according to the operator's manual using the standard analysis protocol and considering the recommendations present in the literature. Considering that bone mineral content (BMC) represents ashed bone, BMC will be converted to total-body Mo by multiplying it by 1.0436.

  20. Fat free mass [ Time Frame: 3 weeks ]

    After the determination of FM, FFM is obtained by subtracting FM from body mass. As the main molecular components are determined, protein is also subtracted from FFM (Protein= FFM-TBW-Mo-Ms). The density of the FFM (FFMd) is also calculated as:

    FFMd = 1/((TBW/0.9937)+(Mo/2.982)+(Ms/3.317)+(Protein/1.34)) Thus, hydration of the FFM can be calculated as TBW/FFM. This value will be used as a reference to test the validity of the algorithm proposed in the AKERN BIA device.


  21. Profile state of mood [ Time Frame: 3 weeks ]
    The profile of mood states (POMS) questionnaire will be applied to assess distinct mood states. This questionnaire will be applied at baseline, before and after the dehydration protocols and after the 4-day intervention. The POMS is a 5-point self-administered scale that assesses various mood states.



Information from the National Library of Medicine

Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the contacts provided below. For general information, Learn About Clinical Studies.


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Ages Eligible for Study:   18 Years to 35 Years   (Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes
Criteria

Inclusion Criteria:

  • Highly trained athletes (i.e., participating in national and international championships and/or ≥6 h of training per week)
  • Athletes considered low drinkers (i.e., total water intake ≤ 35ml/kg/)
  • Aged between 18 and 35 years
  • Living in Lisbon and/or its surroundings
  • All women should have a (self-reported) normal menstrual cycle (i.e., cycles at median intervals of less than 35 days)
  • Completion of the sport's medical examination

Exclusion Criteria:

  • Total water intake above 35ml/kg/day.
  • Clinical history compatible with exertional heat illness (i.e., heat stroke, heat exhaustion, hyperthermia, among other events that suggest poor response to thermically challenging environments)
  • Taking medication known to alter the normal fluid-electrolyte balance, plasma osmolality, urinary osmolality, or the chronotropic response to exercise (e.g., diuretics, antidiuretics, laxatives, oral contraceptives, drugs to control blood pressure (39)
  • Exhibiting self-reported metabolic disorders or malfunction of salivary glands
  • Active smoking status
  • Unwilling to abstain from alcohol during this study
  • Respiratory disorders, including asthma
  • Injuries that would limit exercise performance
  • Mechanical prostheses
  • Pregnancy /planning to get pregnant within the next 8 months
  • Having been pregnant within the past 6 months or breastfeeding
  • Failure to complete the dietary intake and physical activity recording
  • Unable to communicate with local study staff
  • Needle phobia
  • Inability to complete the study within the designated time frame because of plans to move out of the study area or occurrence of competition periods during the study timeframe
  • Inability to attend the visits/appointments and evaluation measurements

Information from the National Library of Medicine

To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.

Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT05380089


Contacts
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Contact: Ruben Francisco, MSc 910943132 ext +351 rubenfrancisco@fmh.ulisboa.pt
Contact: Filipe Jesus, MSc 915970380 ext +351 filipejesus@fmh.ulisboa.pt

Locations
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Portugal
Faculdade Motricidade Humana Recruiting
Lisboa, Portugal, 1495-751
Contact: Analiza Silva, PhD.    +351962903643    analiza@fmh.ulisboa.pt   
Contact: Catarina Nunes, PhD. Student    +351 917 476 565    catarinanunes@fmh.ulisboa.pt   
Sponsors and Collaborators
Faculdade de Motricidade Humana
Investigators
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Principal Investigator: Analiza Silva, PhD Faculdade Motricidade Humana
Publications:
Rodger A, Papies EK. "I don't just drink water for the sake of it": Understanding the influence of value, reward, self-identity and early life on water drinking behaviour. Food Quality and Preference. 2022;99:104576.
EFSA Panel on Dietetic Products N, Allergies. Scientific Opinion on Dietary Reference Values for water. EFSA Journal. 2010;8(3):1459.
Hall JE. Guyton and Hall textbook of medical physiology e-Book: Elsevier Health Sciences; 2015.
Stegeman D, Hermens H. Standards for surface electromyography: The European project Surface EMG for non-invasive assessment of muscles (SENIAM). Enschede: Roessingh Research and Development. 2007:108-12.

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Responsible Party: Faculdade de Motricidade Humana
ClinicalTrials.gov Identifier: NCT05380089    
Other Study ID Numbers: H2O Athletes
First Posted: May 18, 2022    Key Record Dates
Last Update Posted: May 29, 2024
Last Verified: May 2024
Individual Participant Data (IPD) Sharing Statement:
Plan to Share IPD: No

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Studies a U.S. FDA-regulated Drug Product: No
Studies a U.S. FDA-regulated Device Product: No
Keywords provided by Faculdade de Motricidade Humana:
Electromyography
hydration status
neuromuscular activation
muscle strength
muscle power
hydration assessment
dehydration
body composition
Additional relevant MeSH terms:
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Dehydration
Water Intoxication
Water-Electrolyte Imbalance
Metabolic Diseases
Pathologic Processes
Poisoning
Chemically-Induced Disorders