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Completed

NCT Number: NCT05727774

Effect of Water Biking in Hot Versus Neutral Water for Heat Acclimatation

The goal of this clinical trial is to compare the efficiency of water biking training in hot (35°C) versus neutral (25°C) temperature water to elicite heat acclimation in healthy recreative athletes.

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Key information

Conditions

Healthy Heat Exposure

Age range

18 year–60 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Département de Médecine Physique et Réadaptation

Montpellier, 34295, France

About this study

The goal of this clinical trial is to compare the efficiency of water biking training in hot (35°C) versus neutral (25°C) temperature water to elicite heat acclimation in healthy recreative athletes. The main questions it aims to answer are:

  • Does the water biking training protocol in hot versus neutral temperature water improve the time trial in an artificially hot and humid indoor environment?
  • Does the water biking training protocol in hot versus neutral temperature water improve the VO2 max performance and force/velocity profile in neutral indoor environment?
  • What are the main acclimation adaptations (central and cutaneous temperature), heart rate, cardiac function, sweating quality, sleep quality, haematologic profile.

Participants will have to do pre and post training tests in both normal environment (cardiorespiratory stress test, force/velocity profile test, echocardiography) and artificially hot and humid indoor environment (time trial). The training protocols consists in 10 sessions of 1 hour of water bike aerobic training (5 times a week for 2 weeks) at an intensity based on the heart rate corresponding to the 1st respiratory threshold, in hot (interventional group IG: 35°C) versus neutral (control group CG: 25°C) water.

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • Healthy people
  • Sports practicing

Exclusion criteria

  • Acclimatation already done (recent training in hot and/or humid) less than 2 months
  • Heart disease recent or non controlled
  • Heat intolerance
  • Water phobia or inable to swim

Treatment and study plan

Water Biking in hot water condition

Other

Training protocol includes 10 water biking sessions in hot water temperature (35°C) for this group

Water Biking in neutral water condition

Other

Training protocol includes 10 water biking sessions in neutral water temperature (25°C) for this group

Primary outcomes

  1. Change of the distance traveled (meter) on a Time Trial between pre and post training tests in hot and humid atmosphere (environmental room)

    Time frame: The 1st Time Trial will be performed the week preceding the program training. The 2nd Time Trial will be performed the week following the program training

    The participant has to perform the longer distance possible in 30 min on a stationary bike in hot and humid atmosphere (environmental room). The change of distance (measured in meter) will be assessed before and after the 2 weeks training program.

Secondary outcomes

  1. Change in VO2 Max (ml/kg/min) between pre and post training tests in normal environment

    Time frame: The 1st maximal cardiorespiratory test will be performed the week preceding the program training. The 2nd maximal cardiorespiratory test will be performed the week following the program training

    The participant has to perform a maximal cardiorespiratory test on a stationary bike in normal environment. The change in VO2 Max (measured in ml/kg/min) will be assessed before and after the 2 weeks training program.

  2. Change in Maximal Aerobic Power (Watts) between pre and post training tests in normal environment

    Time frame: The 1st maximal cardiorespiratory test will be performed the week preceding the program training. The 2nd maximal cardiorespiratory test will be performed the week following the program training

    The participant has to perform a maximal cardiorespiratory test on a stationary bike in normal environment. The change in Maximal Aerobic Power (measured in Watts) will be assessed before and after the 2 weeks training program.

  3. Change of "global longitudinal strain of left ventricule" (%) measured during an echocardiography between pre and post training tests in normal environment

    Time frame: The 1st echocardiography will be performed the week preceding the program training. The 2nd echocardiography will be performed the week following the program training

    The participant has to pass an echocardiography with specific measurment of "global longitudinal strain of left ventricule" (united in %). The change will be assessed before and after the 2 weeks training program.

  4. Change on central temperature (°C) between pre and post training test in hot and humid atmosphere (environmental room)

    Time frame: The 1st Time Trial will be performed the week preceding the program training. The 2nd Time Trial will be performed the week following the program training

    Central temperature will be measured during Time Trial in hot and humid atmosphere (environmental room). The change on central temperature (measured in °C) will be assessed before and after the 2 weeks training program.

  5. Change on cutaneours temperature (°C) between pre and post training test in hot and humid atmosphere (environmental room)

    Time frame: The 1st Time Trial will be performed the week preceding the program training. The 2nd Time Trial will be performed the week following the program training

    Cutaneous temperature will be measured during Time Trial in hot and humid atmosphere (environmental room). The change on cutaneours temperature (measured in °C) will be assessed before and after the 2 weeks training program.

  6. Change of Na concentration (mmol/L) in the sweat between pre and post training test in hot and humid atmosphere (environmental room)

    Time frame: The 1st Time Trial will be performed the week preceding the program training. The 2nd Time Trial will be performed the week following the program training

    Sweat quality will be measured during Time Trial in hot and humid atmosphere (environmental room). The change of Na concentration (measured in mmol/l) will be assessed before and after the 2 weeks training program.

  7. Change of body weight loss (Kg) between pre and post training test in hot and humid atmosphere (environmental room)

    Time frame: The 1st measure of body weight will be performed the week preceding the program training. The 2nd measure of body weight will be performed the week following the program training

    Body weight loss will be measured before and after Time Trial in hot and humid atmosphere (environmental room). The change of the body weight (measured in Kg) will be assessed between before and after the 2 weeks training program.

  8. Change of Sleep quality between the first and the last training session of water biking

    Time frame: The sleep self-questionnaire will be performed immediately after the first training session (Day 1) and immediately after the last training session (Day 10) of water biking

    Sleep quality will be measured after the first and the last training session using a specific sleep self-questionnaire (PSQI) to detect the effect of hot or neutral water training during the 2 weeks training program.

    PSQI : Pittsburgh Sleep Quality Index. Qualitative questionnaire, no score measured.

  9. Change of force/velocity power (N/m) between pre and post training test

    Time frame: The 1st measure of force/velocity power will be performed the week preceding the program training. The 2nd measure of force/velocity power will be performed the week following the program training

    The participant has to perform a maximal force/velocity test to measure the force/velocity power on a specific fitness testing cycle (Monark 818 E). The change of force/velocity power (measured in N/m) will be assessed between before and after the 2 weeks training program.

  10. Change of sytemic low grade inflammation (CRP = C-Reactive Protein, mg/l) between pre and post training test

    Time frame: The 1st measure of CRP will be performed the week preceding the program training. The 2nd measure of CRP will be performed the week following the program training

    A blood test will be performed to measure the change of CRP concentration (measured in mg/l) between before and after the 2 weeks training program.

  11. Change of haematocrit (%) between pre and post training test

    Time frame: The 1st measure of haematocrit will be performed the week preceding the program training. The 2nd measure of haematocrit will be performed the week following the program training

    A blood test with complete blood count will be performed to measure the change of haematocrit (which is expressed in %) between before and after the 2 weeks training program.

  12. Change of hemoglobin level (g/100ml) between pre and post training test

    Time frame: The 1st measure of hemoglobin level will be performed the week preceding the program training. The 2nd measure of hemoglobin level will be performed the week following the program training

    A blood test with complete blood count will be performed to measure the change of hemoglobin level (measured in g/100ml) between before and after the 2 weeks training program.

  13. Change of Rate of Perceived Effort (RPE) on a Time Trial between pre and post training tests

    Time frame: The 1st Time Trial will be performed the week preceding the program training. The 2nd Time Trial will be performed the week following the program training

    The Borg Rating of Perceived Exertion (RPE) will be used to measure physical activity intensity level. The scale is from 6 to 20. The higher the score is, the higher the perception of effort is.

    RPE will be measured after the first Time Trial and after the second Time Trial (post training protocol).

Sponsors and collaborators

Lead sponsor

University Hospital, Montpellier

Other

Registry information

Official study title

Effect of Hot Versus Neutral Water for Heat Acclimatation and Sport Performance During a Water Biking Training Protocol : Controlled Randomised Study

Acronym: THERMIDOR

Important dates

Study start
2023
Primary completion
2023
Study completion
2023
First posted
Feb 14, 2023
Registry last updated
Jun 12, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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