How accurate are the wrist-based heart rate monitors during walking and running activities? Are they accurate enough?

Abstract

BackgroundHeart rate (HR) monitors are valuable devices for fitness-orientated individuals. There has been a vast influx of optical sensing blood flow monitors claiming to provide accurate HR during physical activities. These monitors are worn on the arm and wrist to detect HR with photoplethysmography (PPG) techniques. Little is known about the validity of these wearable activity trackers.AimValidate the Scosche Rhythm (SR), Mio Alpha (MA), Fitbit Charge HR (FH), Basis Peak (BP), Microsoft Band (MB), and TomTom Runner Cardio (TT) wireless HR monitors.Methods50 volunteers (males: n=32, age 19–43 years; females: n=18, age 19–38 years) participated. All monitors were worn simultaneously in a randomised configuration. The Polar RS400 HR chest strap was the criterion measure. A treadmill protocol of one 30 min bout of continuous walking and running at 3.2, 4.8, 6.4, 8.0, and 9.6 km/h (5 min at each protocol speed) with HR manually recorded every minute was completed.ResultsFor group comparisons, the mean absolute percentage error values were: 3.3%, 3.6%, 4.0%, 4.6%, 4.8% and 6.2% for TT, BP, RH, MA, MB and FH, respectively. Pearson product-moment correlation coefficient (r) was observed: r=0.959 (TT), r=0.956 (MB), r=0.954 (BP), r=0.933 (FH), r=0.930 (RH) and r=0.929 (MA). Results from 95% equivalency testing showed monitors were found to be equivalent to those of the criterion HR (±10% equivalence zone: 98.15–119.96).ConclusionsThe results demonstrate that the wearable activity trackers provide an accurate measurement of HR during walking and running activities.

The Accuracy of Wrist-worn Heart Rate Monitors across a Range of Exercise Intensities

“…Despite strong correlations with criterion measurements and the absence of statistically significant differences, the failure of the wrist-worn devices to consistently produce accurate HR readings is consistent with reports on similar devices [8,9,10]. Previous research has attributed inconsistencies in HR readings, in part, to artefacts from excessive hand/wrist movement during running [6,9].…”

“…Previous wrist-worn HR monitor studies have suggested either an improvement [8], or a reduction [9,10] in precision as exercise intensity increases; the former attributed to increases in blood perfusion, and the latter to increased hand/wrist movement at faster running speeds. The present study is the first to investigate the precision of wrist-worn HR monitors during incremental exercise at various relative, rather than fixed, exercise intensities.…”

“…[7] Recent evidence suggests that the PPG method has acceptable validity in the measurement of HR during walking and running activities. [8] However, some studies [9,10] have reported that wrist-worn devices become less accurate in measuring HR as exercise intensity increases, possibly due to increases in upper body movement during faster running speeds, rather than an error in the device per se. In contrast, Stahl and colleagues [8] reported an increase in HR precision at raster running speeds, possibly due to an enhancement in blood perfusion.…”

“…[8,9,10] As exercise intensities for each participant were not prescribed relative to the level of CRF, this could influence the precision of the HR response due to participants performing exercise within different intensity domains. For example, running at a particular speed, could be within the moderate intensity domain for one individual; whereas the same speed could be vigorous, potentially non steady-state, exercise for an individual with a lower level of CRF.…”

Influence of Footwear on Individual Performance during Prolonged Standing

“…Fitbit Charge HR™ device accurately measure heart rate [23]. Wearable activity trackers provide an accurate measurement of heart rate during walking and running activities [24].…”