Concurrent Heart Rate Validity and Reliability of Polar Verity Sense Devices During Light and Moderate Intensity Resistance Training in Recreationally Active Adults

Our laboratory previously determined that while wrist-worn wearable technology devices (e.g. Garmin watches) are not valid or reliable for heart rate, bicep-worn wearable technology devices (e.g., Polar Verity Sense) were valid and reliable for heart rate during light intensity resistance training (RT). However, these devices have never been tested for validity or reliability with varied intensities during resistance training. PURPOSE: To determine the concurrent validity and reliability of identical Polar Verity Sense bicep-worn devices to assess valid measures of average and maximum heart rate (HR) during light and moderately heavy RT. METHODS: Twenty adults (n=16 male, n=4 female, age: 25.65±8.59 yrs; mass: 92.79±29.71 kg; height: 179.40±9.81) cm) who have consistently engaged in resistance training for at least one month on two or more days a week completed 4 sets of 6 repetitions at a light intensity (3-4 RPE scale) and moderately heavy intensity (6-8 RPE) of the deadlift exercise with 1-1.5 minutes of rest between sets. Two Polar Verity Sense devices were evaluated, along with the Polar H10 chest strap (average/maximal HR criterion). Data were analyzed for validity (Mean Absolute Percent Error [MAPE] and Lin’s Concordance Coefficient [CCC]) and reliability (Coefficient of Variation [CV]), with predetermined thresholds for validity of MAPE0.70 and reliability of CVRESULTS: Both Verity #1 and #2 were valid and reliable for average HR (MAPE range: 3.5-5.7%; CCC range: 0.81-0.94; CV range: 2.0-3.4%) and maximal HR (MAPE range: 3.1-5.7%; CCC range: 0.74-0.94; CV range: 1.9-3.4%), in both intensity conditions. CONCLUSIONS: Bicep-worn Polar Verity Sense devices were found to be valid and reliable measurement tools for average and maximal HR during both light and moderate intensity RT. Therefore, these devices can be utilized within acute RT or potentially other settings that vary in intensity and require precise and repeatable HR monitoring.