Examining the Accuracy of the Polar A360 Monitor

Abstract

Rider, BC, Conger, SA, Ditzenberger, GL, Besteman, SS, Bouret, CM, and Coughlin, AM. Examining the accuracy of the Polar A360 monitor. J Strength Cond Res 35(8): 2165–2169, 2021—The purpose of this study was to determine the accuracy of the Polar A360 heart rate (HR) monitor during periods of rest, walking/running, and active/passive recovery from exercise. Thirty collegiate athletes (women n = 15 and men n = 15) wore an A360 monitor and a previously validated chest HR monitor (Polar RS400) that served as the criterion measurement across a range of resting and walking/running intensities. First, subjects rested in a supine, seated, and standing position. Next, each subject walked on a treadmill at 1.6 kilometers per hour (kph). Speed was increased by 1.6 kph every 2 minutes until volitional fatigue. Then, subjects walked at 4.8 kph followed by a seated recovery stage. Heart rate was recorded in 30-second increments. Total mean difference in HR readings, percent accuracy, and intraclass correlation coefficient (ICC) analysis established the level of agreement between devices. Bland-Altman plots and a regression were used to examine the agreement between devices. The A360 demonstrated a strong correlation with the RS400 (r 2 = 0.98) across time points. The analysis of variance with repeated measures indicated an overall significant difference (p < 0.001) between devices. The A360 significantly underestimated HR during the 6.4-kph speed only (p < 0.05) (effect size 0.26). The greatest percent accuracy occurred during rest (91%) and recovery (90%). An ICC of 0.98 (SEM: 0.35) demonstrates a strong level of agreement between devices. The A360 is accurate at rest and during various walking and running speeds and thus is a device that can be used with confidence by athletes for specific training purposes. Future research should examine accuracy during weight training and other sport-specific activities.

Validity of the Polar M430 Among Females of Varying Fitness Levels, Body Fat Percentage, and Reported Physical Activity

“…They further explained that a change in movement and gait pattern could have been a possible reason why the accuracy of the A360 was impacted at this stage. During the resting stages, the A360 demonstrated the highest accuracy (91%) but decreased during walking (71%) and then increased at running speeds (79%) (Rider et al, 2019).…”

“….75) throughout the entire test(Boudreaux et al, 2018). This study suggests that both wrist worn and chest strap monitors can provide valid measures of one's HR at rest, but may begin to worsen as exercise intensity increases Rider et al (2019). examined the accuracy of the wrist worn Polar A360 among 30 athletes.…”

“…However, HR measurement was significantly underestimated during a 6.4 kph speed during the graded exercise test (p < 0.05) (Rider et al, 2019). Rider et al (2019) explained that during this stage of the exercise protocol, participants alternated between walking and jogging. They further explained that a change in movement and gait pattern could have been a possible reason why the accuracy of the A360 was impacted at this stage.…”

“…This study showed that a group of commercially available wrist worn monitors will give comparable HR results to chest strap monitors. (Rider et al, 2019).…”

“…However, this is mostly seen during low intensity exercise and begins to vary as exercise intensity increases (Boudreaux et al, 2018;Jo et al, 2016). Other monitors have shown to be significantly different from the gold standard during stages of intensity that change upper body movement and gait patterns (Rider et al, 2019). The mode of exercise can also cause variation in the validity of these monitors (Horton et al, 2017;Jo et al, 2016), as well as the model of the monitor (Boudreaux et al, 2018;Gillinov et al, 2017).…”