Thermoregulation During a 25-km Open Water Race (THERMO25)

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

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.

Study Overview

• Status: Completed
• Conditions: Hypothermia Due to Cold Environment
• Intervention / Treatment: Other: Swimming participants in the 25-km

• Study Type: Observational
• Enrollment (Actual): 24

Contacts and Locations

Study Locations

• France
  • Caen, France, 14000
    • CHU Caen Normandie

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 15 years to 45 years (Child, Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

• Sampling Method: Probability Sample

Study Population

All the competitors of the 25-km French Open Water Championship who volunteered for this study

Description

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

Study Plan

How is the study designed?

Design Details

• Observational Models: Cohort
• Time Perspectives: Prospective

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Change in Body Core Temperature	Measurement of Body Core Temperature using an ingestible electronic sensor (e-Celsius®, BodyCap , Caen, France) which provide a continuous validated measurement	Continuous measurement was collected from 30 minutes before the race until 2 hours after the end of the race for each swimmer
Change in Water Temperature	Measurement of the Water Temperature using an electronic sensor (iButton® Maxim Integrated) which provide a continuous validated measurement	Continuous measurement was collected from 30 minutes before the race until 2 hours after the end of the race for each swimmer

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body composition, body mass	Body mass (in kg) was measured using bioelectrical impedance analysis (mBCA 525, Seca, Germany).	One measurement assessed the day before the race
Body composition, fat mass	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).	One measurement assessed the day before the race
Body composition, fat-free mass	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).	One measurement assessed the day before the race
Body composition, muscle mass	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).	One measurement assessed the day before the race
Perception of Cold	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)	One measurement assessed immediately at the end of the race
Performance	Time at each lap and swimming race timing was collected using the official swimming timing from the race organisers and French Federation	Time at each lap of 2500m and at the end of the race
Dropout rate	Swimmers who dropout were identified and cause for dropout was collected	During the swimming race and data were collected immediately after dropout for each swimmer who dropped out

Collaborators and Investigators

• Sponsor: University Hospital, Caen
• Investigators: Principal Investigator: Joffrey Drigny, MD MSC, CHU Caen Normandie

Study record dates

Study Major Dates

• Study Start (Actual): March 1, 2019
• Primary Completion (Actual): May 26, 2019
• Study Completion (Actual): June 3, 2020

Study Registration Dates

• First Submitted: June 27, 2020
• First Submitted That Met QC Criteria: July 1, 2020
• First Posted (Actual): July 7, 2020

Study Record Updates

• Last Update Posted (Actual): July 7, 2020
• Last Update Submitted That Met QC Criteria: July 1, 2020
• Last Verified: July 1, 2020

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Body Temperature Changes; Hypothermia
• Other Study ID Numbers: THERMO25

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No
• product manufactured in and exported from the U.S.: No