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Completed

NCT Number: NCT04460339

Thermoregulation During a 25-km Open Water Race

Open water swimming is a swimming discipline which takes place in outdoor water such as open oceans, lakes, and rivers. Elite swimmers are exposed to hypothermia when swimming in cold water, especially in long duration races, such as the 25-km race. The objective of this study is to evaluate the change in body core temperature in swimmers with continuous temperature monitoring during a 25-km race. The secondary objective is to identify the predictors of hypothermia and hypothermia-related drop-out.

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Key information

Conditions

Hypothermia Due to Cold Environment

Age range

15 year–45 year

Sex eligibility

All sexes

Study type

Observational

Primary location

CHU Caen Normandie

Caen, 14000, France

Who can participate

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

Inclusion criteria

  • competitors of the 25-km French Open Water Championship
  • participants who volunteered for this study
  • written consent was obtained from all participants, as well as their legal representatives when applicable (i.e. parents for under age participants).

Exclusion criteria

  • swallowing disorders
  • transit disorders
  • MRI scheduled within 48 hours

Treatment and study plan

Swimming participants in the 25-km

Other

The 25-km race was the French national Open Championship event and participants were the swimmers registered for the race who volunteered to participate in this study

Primary outcomes

  1. Change in Body Core Temperature

    Time frame: Continuous measurement was collected from 30 minutes before the race until 2 hours after the end of the race for each swimmer

    Measurement of Body Core Temperature using an ingestible electronic sensor (e-Celsius®, BodyCap , Caen, France) which provide a continuous validated measurement

  2. Change in Water Temperature

    Time frame: Continuous measurement was collected from 30 minutes before the race until 2 hours after the end of the race for each swimmer

    Measurement of the Water Temperature using an electronic sensor (iButton® Maxim Integrated) which provide a continuous validated measurement

Secondary outcomes

  1. Body composition, body mass

    Time frame: One measurement assessed the day before the race

    Body mass (in kg) was measured using bioelectrical impedance analysis (mBCA 525, Seca, Germany).

  2. Body composition, fat mass

    Time frame: One measurement assessed the day before the race

    Fat mass (in kg, % of body mass [fat mass and body mass were combined to report % of body mass) was measured using bioelectrical impedance analysis (mBCA 525, Seca, Germany).

  3. Body composition, fat-free mass

    Time frame: One measurement assessed the day before the race

    Fat-free mass (in kg, % of body mass [fat-free mass and body mass were combined to report % of body mass) was measured using bioelectrical impedance analysis (mBCA 525, Seca, Germany).

  4. Body composition, muscle mass

    Time frame: One measurement assessed the day before the race

    Muscle mass (in kg, % of body mass [muscle mass and body mass were combined to report % of body mass) was measured using bioelectrical impedance analysis (mBCA 525, Seca, Germany).

  5. Perception of Cold

    Time frame: One measurement assessed immediately at the end of the race

    Immediately at the end of the race participants' perception of cold was assessed using the Cold Discomfort Scale (CDS, with rating from 0-to-10 over 10, where 0 indicates no experience of cold and 10 indicates unbearable cold)

  6. Performance

    Time frame: Time at each lap of 2500m and at the end of the race

    Time at each lap and swimming race timing was collected using the official swimming timing from the race organisers and French Federation

  7. Dropout rate

    Time frame: During the swimming race and data were collected immediately after dropout for each swimmer who dropped out

    Swimmers who dropout were identified and cause for dropout was collected

Sponsors and collaborators

Lead sponsor

University Hospital, Caen

Other

Registry information

Official study title

Changes in Body Core Temperature During a 25-km Open Water Race in Elite Swimmers: Identifying Predictors for Hypothermia and Dropouts

Acronym: THERMO25

Important dates

Study start
2019
Primary completion
2019
Study completion
2020
First posted
Jul 7, 2020
Registry last updated
Mar 26, 2025

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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