Reliability and Validity of the CORE Sensor to Assess Core Body Temperature during Cycling Exercise.

Nina Verdel,Tim Podlogar,Urša Ciuha,Tadej Debevec,Hans-Christer Holmberg,Matej Supej

doi:10.3390/s21175932

Abstract

Monitoring core body temperature (Tc) during training and competitions, especially in a hot environment, can help enhance an athlete’s performance, as well as lower the risk for heat stroke. Accordingly, a noninvasive sensor that allows reliable monitoring of Tc would be highly beneficial in this context. One such novel non-invasive sensor was recently introduced onto the market (CORE, greenTEG, Rümlang, Switzerland), but, to our knowledge, a validation study of this device has not yet been reported. Therefore, the purpose of this study was to evaluate the validity and reliability of the CORE sensor. In Study I, 12 males were subjected to a low-to-moderate heat load by performing, on two separate occasions several days apart, two identical 60-min bouts of steady-state cycling in the laboratory at 19 °C and 30% relative humidity. In Study II, 13 males were subjected to moderate-to-high heat load by performing 90 min of cycling in the laboratory at 31 °C and 39% relative humidity. In both cases the core body temperatures indicated by the CORE sensor were compared to the corresponding values obtained using a rectal sensor (Trec). The first major finding was that the reliability of the CORE sensor is acceptable, since the mean bias between the two identical trials of exercise (0.02 °C) was not statistically significant. However, under both levels of heat load, the body temperature indicated by the CORE sensor did not agree well with Trec, with approximately 50% of all paired measurements differing by more than the predefined threshold for validity of ≤0.3 °C. In conclusion, the results obtained do not support the manufacturer’s claim that the CORE sensor provides a valid measure of core body temperature.

Highlights

The main findings were that the reliability of the CORE sensor was acceptable, with a non-significant mean bias between Trials 1a and 1b in Study I of only 0.02 ◦ C
Rectal sensor, the Trec indicated by the CORE sensor demonstrated poor agreement during cycling under conditions of both low-to-moderate and moderate-to-high heat load, with differences between the devices that were greater than the predefined acceptable level of ≤ 0.3 ◦ C being associated with 45% and 51% of all values measured, respectively
These findings do not support the claim that the CORE sensor provides a valid measure of core body temperature

Summary

Introduction

Intense exercise in such a hot environment impairs athletic performance [3], causes a rise in core body temperature (Tc ) and increases the risk for potentially life-threatening exertional heat illness (heat stroke) associated with a. To offset the impact of thermally stressful environmental conditions, numerous strategies have been developed to help manage heat stress. Out of these strategies, heat acclimation and heat acclimatization appear to provide optimal benefits [5]. The training guidelines advise athletes to exercise for a prolonged time (e.g., 60–90 min) at Tc above 38.5 ◦ C [6,7]. It is of utmost importance to provide athletes and coaches with a valid, reliable, and applicable strategy to monitor Tc

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Results

Discussion

Conclusion