Thermoregulation During a 25-km Open Water Race

Study Overview
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Brief Summary
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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.

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

Conditions
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Hypothermia Due to Cold Environment

Intervention / Treatment
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* Other: Swimming participants in the 25-km


Participation Criteria
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Eligibility Criteria
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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

Ages Eligible for Study
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Minimum Age: 15 Years
Maximum Age: 45 Years

Sexes Eligible for Study
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All

Study Plan
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How is the study designed?
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Arms and Interventions

| Intervention/Treatment |
| --- |
|Other: Swimming participants in the 25-km|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|

What is the study measuring?
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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 |