Authors: Marcus M Lawrence, Merrill Funk, Jeffrey C Cowley, Amanda Hawkes, Aaron McKenzie, Alexandra Routsis, Wesley Ziegler, Talon Thornton, Spencer Maxwell, Korina Ziegler, James Navalta
Mentors: Marcus Lawrence
Insitution: Southern Utah University
American College of Sports Medicine has again found that wearable technology and resistance training (RT) are two of the top 5 fitness trends in 2023. Our lab recently found that the bicep-worn Polar Verity device was valid and reliable for measuring average and maximal heart rate (HR) during light intensity circuit RT. However, no study has examined other bicep worn devices during RT while also examining heavier intensities. PURPOSE: To determine the concurrent validity of identical Polar OH1 (x2) and Verity Sense (x2) bicep-worn devices in recording average and maximal HR following moderately heavy RT. METHODS: Twenty-one adult participants completed this study (n=10 female, n=11 male; age: 26.1±9.2 yrs; height: 171.3±9.4 cm; mass: 71.4±18.2 kg; RT experience: 5.7±4.9 yrs). The four bicep devices (Polar OH1 x2 and Polar Verity Sense x2) were worn along with the Polar H10 chest strap, criterion for HR. Participants completed 8 supersets of the reverse lunge and shoulder press exercises using dumbbells at a light (4 sets) and moderately heavy (4 sets) intensity with 1 superset of 6 repetitions per exercise (12 repetitions per superset) and 1 min rest between supersets. Data was analyzed for validity (Mean Absolute Percent Error [MAPE] and Lin’s Concordance Coefficient [CCC]), with predetermined thresholds of MAPE<10% and CCC>0.70. Paired t-tests were used to determine differences (p<0.05). RESULTS: For average or maximal HR, neither the Polar Verity Sense 1 (127.2±17.8 or 151.5±16.7bpm) or 2 (125.7±18.8 or 147.9±18.9bpm) or the Polar OH1 1 (128.7±18.5 or 154.5±18.1bpm) or 2 (129.5±18.2 or 156.4±17.4bpm) were significantly (p range: 0.14-0.97) different than the criterion (128.6±19.2 or 149.3±18.0bpm). However, the Polar Verity 1 and 2 were not considered valid for average HR (MAPE range:16.17-17.57%; CCC range: 0.07-0.13) or maximal HR (MAPE range: 11.60-13.33%; CCC range: 0.02-0.29). The Polar OH1 1 and 2 devices were not considered valid, either, for average HR (MAPE range: 17.22-17.25%; CCC range: 0.08-0.09) or maximal HR (MAPE range: 13.24-13.92%; CCC range: .024-0.27). CONCLUSION: Despite our lab previously finding the Polar Verity as valid for HR measurements during light intensity RT, the current bicep-worn devices should not be utilized during heavier intensity RT for accurate HR measurements. Individuals resistance training and utilizing bicep-worn devices for heart rate should use them cautiously.