Core Temperature Afterdrop in Cold-water Swimming (THERMOCOLD)

Analysis of Core Temperature Afterdrop and Factors Associated With Afterdrop in Cold-water Swimming

A significant risk associated with hypothermia during exercise in a cold environment is the core temperature (T°core) afterdrop, which corresponds to a continuous fall in T°core during rewarming after hypothermia. However, the rate and predictors of the afterdrop are unclear, particularly during prolonged cold water swimming.

The investigators propose to measure the changes in T°core during and after a cold water swim at 12.5-13°C qualifying for English Channel swim and to test the impact of anthropometric and swimming parameters on the duration of the T°core afterdrop. The hypotheses are that afterdrop is common during a prolonged cold water swimming event and that protective factors against T°core drop during cold water swimming (increased body fat and BMI) might, conversely, be associated with prolonged afterdrop.

Study Overview

• Status: Completed
• Conditions: Hypothermia, Accidental; Cold Water Swimming
• Intervention / Treatment: Other: Swimming participants in the 6-hour cold water swim

• Study Type: Observational
• Enrollment (Actual): 15

Contacts and Locations

Study Locations

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

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 65 years (Adult, Older Adult)
• Accepts Healthy Volunteers: Yes

• Sampling Method: Probability Sample

Study Population

Swimmers participating in the 6-hour cold-water swim, qualifying for the English Channel swim at the Channel Swim Camp (Dinard, France).

Description

Inclusion Criteria:

• swimmers taking part in the Channel Swim Camp
• swimmers above 18 years of age
• swimmers willing and able to give informed consent for participation in the study

Exclusion Criteria:

• swallowing disorder
• chronic gastrointestinal disease
• MRI scheduled within 48 hours after the race.

Study Plan

How is the study designed?

Number of groups / cohorts

1

Cohorts and Interventions

Group / Cohort	Intervention / Treatment
Cold water swimmers; swimmers participating in the 6-hour cold water swim, qualifying for the English Channel Swim	Other: Swimming participants in the 6-hour cold water swim; The 6-hour cold water swim was the qualifying swim for the English Channel swim during the Channel Swim Camp Dinard 2021 and participants were the swimmers registered for the 6-hour cold water swim who volunteered to participate in this study

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

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
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
Body composition, body 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
Distance	Distance of the swimming	The distance of swimming was collected from the organisers immediately after the race
Duration	Duration of the swimming	The duration of swimming was collected from the organisers immediately after the race
Individual characteristics, gender	The variable collected was the gender of participants	One evaluation assessed the day before the race
Individual characteristics, age	The variables collected was the age of participants	One evaluation assessed the day before the race
Individual characteristics, swimming habits	The variables collected was the swimming distance per week (total, swimming pool and open water)	One evaluation assessed the day before the race
Individual characteristics, training in cold environment	The variable collected was the type of specific training in cold environment (yes/no)	One evaluation assessed the day before the race

Collaborators and Investigators

• Sponsor: University Hospital, Caen
• Collaborators: INSERM UMR U1075 Comète GIP Cyceron, unicaen, Caen Normandie

Study record dates

Study Major Dates

• Study Start (Actual): May 21, 2021
• Primary Completion (Actual): May 23, 2021
• Study Completion (Actual): August 19, 2021

Study Registration Dates

• First Submitted: April 17, 2022
• First Submitted That Met QC Criteria: June 3, 2022
• First Posted (Actual): June 8, 2022

Study Record Updates

• Last Update Posted (Estimated): March 26, 2025
• Last Update Submitted That Met QC Criteria: March 24, 2025
• Last Verified: June 1, 2022

More Information

Terms related to this study

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

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: UNDECIDED

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No