The Impact of Resistance Exercise Intensity and Position of Wrist-Worn Wearable Technology Devices Measuring Heart Rate Validity During an Acute Session in Recreationally Active Adults

Authors

Catalina M. Kerwin, Southern Utah UniversityFollow
Jae Bovell, University of Nevada, Las VegasFollow
Kynlee Sperry, Southern Utah UniversityFollow
Juni TimminsFollow
Jose Vasquez, University of Nevada Las VegasFollow
Setareh ZareiFollow
Jeff Guzman, University of Nevada, Las VegasFollow
Nathaniel Bodell, California State University - San BernardinoFollow
James W. Navalta FACSM, University of Nevada, Las VegasFollow
Marcus M. Lawrence, Southern Utah UniversityFollow

Abstract

Wearable technology is widely used in recreational exercise. We recently found that wrist-worn devices (e.g., Garmin Instinct) were not valid or reliable for measuring average or maximal heart rate (HR) during resistance training (RT). We postulated that lack of accuracy could be due to the intensity of RT or even positioning of the device on the wrist. PURPOSE: To determine the impact of RT intensity or wrist position on average or maximal HR validity and reliability of identical wrist-worn Garmin Instincts. METHODS: 21 recreationally active adults (n=4 females, n=17 males, age: 25.7±8.6 yrs; mass: 92.8±29.7 kg; height: 179.4±9.8 cm) completed 4 sets of 6 repetitions of the deadlift exercise at a light (RPE 3-4) and moderate-to-high (RPE 6-8) intensity, with 1-1.5 min. rest between sets. Four Garmin Instinct (2 each placed on the inner and outer wrist) 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 Bland-Altman analysis, with predetermined thresholds of MAPE0.70. Reliability was examined using intraclass correlation coefficients (ICC) and coefficients of variation (CV). RESULTS: HR measurement accuracy was significantly affected by both placement and exercise intensity. Averaged devices for outer wrist placement at light intensity demonstrated the highest agreement for average & max HR (MAPE: 9.1% & 9.5%, CCC: 0.54 & 0.58, CV: 2.7% & 2.9%, ICC: 0.54 & 0.59), and similarly at moderate-to-high intensity (MAPE: 15.9% & 13.0%, CCC: 0.59 & 0.54, CV% 3.3% & 3.6%, ICC: 0.59 & 0.55). Whereas inner wrist placement averages showed poorer validity and reliability under light intensity for average and max HR (MAPE: 16.5% & 18.0%, CCC: 0.34 & 0.11, CV: 9.2% & 9.7%, ICC: 0.34 & 0.27) and moderate-to-high intensity (MAPE: 28.0% & 27.7%, CCC: 0.17 & 0.05, CV: 10.6% & 8.5%, ICC: 0.18 & 0.05). Both placements demonstrated increased error during moderate-to-high intensity, with widened Bland–Altman limits of agreement and reduced reliability. CONCLUSION: Wrist-worn Garmin Instinct monitors show limited validity for HR monitoring during RT, especially at higher intensities and also considering wrist placement, and thus a chest strap is recommended.

Recommended Citation

Kerwin, Catalina M.; Bovell, Jae; Sperry, Kynlee; Timmins, Juni; Vasquez, Jose; Zarei, Setareh; Guzman, Jeff; Bodell, Nathaniel; Navalta, James W. FACSM; and Lawrence, Marcus M. (2025) "The Impact of Resistance Exercise Intensity and Position of Wrist-Worn Wearable Technology Devices Measuring Heart Rate Validity During an Acute Session in Recreationally Active Adults," International Journal of Exercise Science: Conference Proceedings: Vol. 14: Iss. 5, Article 63.
Available at: https://digitalcommons.wku.edu/ijesab/vol14/iss5/63