Intra-rater reliability and repeatability of pulse oximetry values obtained before, between sets, and after resistive exercise

Abstract

BACKGROUND: Pulse oximetry measures heart rate (HR) and percent oxygen saturation (SpO2). For aerobic exercise, whereby cellular oxygen demand and delivery are elevated and maintained for extended periods, HR and SpO2 values are consistent when measured by pulse oximetry. Yet due to its intermittent nature, HR and SpO2 values from resistive exercise may exhibit lower data reliability and repeatability. OBJECTIVE: Assess intra-rater reliability and repeatability of pulse oximetry HR and SpO2 values from two identical resistive exercise protocols. METHODS: Subjects (n= 32) performed two calf press workouts on a flywheel-based ergometer as HR and SpO2 were measured before, between sets, and after exercise. Workouts entailed a 4-set 15-repetition protocol separated by 120-second rests. Intra-rater reliability was assessed with intraclass correlation coefficients (ICC). Repeatability was measured by the smallest real difference in absolute and relative terms. RESULTS: ICC and standard error of estimate results for HR ranged from 0.60–0.79 and 9.1–13.0 respectively. SpO2 ICC and standard error of estimate results ranged from 0.16–0.71 and 1.44–4.33 respectively. Between sets, smallest real difference values tended to be less for HR. CONCLUSIONS: Results demonstrate acceptable intra-rater reliability and repeatability for HR, but not SpO2 which we attribute to the exercise mode and protocol examined.