Investigating Respiratory Frequency as a Core Temperature Proxy in Division 1 American Football

Authors

Beverly Albert, Rocky Mountain University of Health ProfessionsFollow
Shane Draper, Utah Valley UniversityFollow
Paula Johnson, Rocky Mountain University of Health Professions
Victor Romano, Rocky Mountain University of Health Professions
Scott Willis, University of Utah

Abstract

Exertional heat illness (EHI) is a leading cause of preventable sudden death in sports. American football (AmFb) accounts for 75% of reported heat-related illnesses in NCAA sports. EHI fatalities in AmFb have surpassed those from direct trauma since 1990, mainly occurring during preseason practices when wet bulb globe temperatures (WBGT) exceed 27.8°C. Although internal temperature monitoring has been explored, the relationship between electrocardiogram-derived respiratory frequency (EDR) and core temperature (Tc) remains undefined. PURPOSE: This study aims to evaluate EDR as a non-invasive, real-time monitoring strategy for heat stress compared to ECG-Tc during preseason practices. METHODS: Six University of Utah football players (20.3 ± 1.6 years) were recruited for the study. Following the pilot phase, data collection occurred during early preseason, which included observing back-to-back afternoon practice sessions. Participants ingested a BodyCap thermometer capsule the morning of their first scheduled practice to measure Tc. Physiological data (e.g., heart rate) were collected with ECG-integrated Catapult sensors. Individuals met with the researcher following observed sessions to synthesize data. Practice conditions were also documented. Investigators preprocessed and analyzed data in RStudio. RESULTS: Preliminary Pearson correlation analyses showed a moderate, positive relationship between measured Tc and HR-derived Tc estimates (r = 0.52, p < 0.001), but no significant relationship with EDR (r = 0.34, p = 0.57); additional data will be incorporated as analyses progress. CONCLUSION: Early findings indicate that ECG-Tc better represents actual Tc values than EDR; ongoing analyses will further inform ecological monitoring strategies to support athlete safety.

Recommended Citation

Albert, Beverly; Draper, Shane; Johnson, Paula; Romano, Victor; and Willis, Scott (2025) "Investigating Respiratory Frequency as a Core Temperature Proxy in Division 1 American Football," International Journal of Exercise Science: Conference Proceedings: Vol. 14: Iss. 5, Article 66.
Available at: https://digitalcommons.wku.edu/ijesab/vol14/iss5/66