Real-Time Monitoring of Biometric Responses During a 200-km Ultra-Endurance Race Across the Desert

Ultra-endurance sports challenge athlete health, with these risks exacerbated by environmental extremes and/or remoteness of competition. Therefore, this study aimed to use real-time monitoring technology to characterise and monitor physiological/biomechanical responses during SAMLA 2023, a 200-km multidiscipline (swim, run, bike, and kayak) ultra-endurance race, encompassing cool and warm desert environmental conditions (16°C-28°C). Within a cross-sectional observational study design, 18 males (total entrants: 318) were instrumented with wearable/ingestible sensors measuring physiological [heart rate and core (Tc)/skin (Tsk) temperature], biomechanical [gait] and location-based [Global Positioning System (GPS)] metrics. Sensors connected to a smartphone application via Bluetooth, which saved and transmitted data to a cloud-based dashboard in real-time. Participants were on-course for an accumulated ∼668 h. ∼662 h of GPS data were displayed in real-time with the longest individual data capture of ∼57 h. Physiological/biomechanical data were acquired for x̄: ∼42% (range: ∼38%-∼49%) of the participant on-course time. Hypo/hyperthermic Tc's were seen (x̄: 37.8°C range: 35.7°C-39.2°C). Tsk (28°C: 11.7°C-38.4°C) in response to the varied in-race environmental challenges (16°C-28°C ambient temperature) and heart rate (111 b·min^-1: 37 b·min^-1-179 b·min^-1) varied markedly. One participant was hospitalised without presentation in physiological data. Biomechanical data had significant data loss and quality issues and are not presented. Developments in real-time monitoring technology, acknowledging limitations observed here (physiological/biomechanical data acquisition), may allow combined in-race GPS and physiological data (e.g., Tc/Tsk) to be used during ultra-endurance sport to prospectively protect athlete health. GPS/physiological data alone may not identify medical emergencies, and medical teams must remain alert to medical events.