Reliability and validity of the CORE sensor to assess core body temperature during cycling exercise
Open accessAbstract
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.
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Given the acceptable reliability, CORE sensors can be used to assess group mean responses but not for individualised accuracy.
“Given the acceptable reliability,58 CORE sensors can be used to assess group mean responses but not for individualised accuracy.”
From Influence of habitual physical activity on cognitive performance of healthy young adults after passive heat exposure (2026) · cites this paper as [58]
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Considerations for the measurement of core, skin and mean body temperatures
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Zhuo, F., Gaurani, R. J., Low, I. C. C., Deshayes, T. A., Lee, J. K. W., Cheung, S. S., Choo, P. L., & Tan, X. R. (2026) · Journal of Exercise Science & Fitness · doi:10.1016/j.jesf.2025.200436 · Cited by 1 · see citing works
- Authors
- Verdel, N., Podlogar, T., Ciuha, U., Holmberg, H.-C., Debevec, T., & Supej, M.
- Affiliations
- Mid Sweden University (SE)
- University of Primorska (SI)
- Jožef Stefan Institute (SI)
- Luleå University of Technology (SE)
- University of Ljubljana (SI)
- Corresponding author
- Verdel, Nina
- Venue
- Sensors
- Publisher
- MDPI AG
- Published
- 2021-09-03
- Volume
- 21
- Issue
- 17
- Pages
- 5932
- ISSN
- 1424-8220 (ISSN-L)
- PMC
- PMC8434645
- OpenAlex
- W3197036417
- Cited by
- 89
- References
- 1
- Citations by year
- 2026: 28 · 2025: 23 · 2024: 15 · 2023: 13 · 2022: 9 · 2021: 1
- FWCI
- 5.81
- Type
- journal article
- Language
- en
- Open access
- gold
- doi.org
- Licence
- Locations
- Sensors (publishedVersion, cc-by)
- PubMed Central (publishedVersion, cc-by)
- PubMed (publishedVersion)
- Repository of the University of Ljubljana (University of Ljubljana) (publishedVersion, cc-by)
- Diva portal (Dalarna University Library) (submittedVersion, other-oa)
- DOAJ (DOAJ: Directory of Open Access Journals) (submittedVersion, cc-by-sa)
- University of Birmingham Research Portal (University of Birmingham) (submittedVersion, cc-by)
- University of Birmingham Research Portal (University of Birmingham) (submittedVersion, other-oa)
- Funders
- Horizon 2020 (824984)
- Javna Agencija za Raziskovalno Dejavnost RS (J5-9350, P5-0147)
- Topics
- Health Sciences › Medicine › Physiology › Thermoregulation and physiological responses
- Health Sciences › Medicine › Orthopedics and Sports Medicine › Sports Performance and Training
- Health Sciences › Medicine › Complementary and alternative medicine › Cardiovascular and exercise physiology
- Keywords
- core body temperature, non-invasive temperature monitoring, sensor validation, measurement reliability, cycling exercise, heat load, rectal temperature, heatstroke prevention, thermal comfort
- MeSH terms
- Body Temperature, Hot Temperature, Humans, Male, Reproducibility of Results, Exercise, Heat Stroke
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