Validity of Activity Trackers in Estimating Energy Expenditure During High-Intensity Functional Training

• Published in: Research quarterly for exercise and sport Vol. 90; no. 3; pp. 377 - 384
• Main Authors: Morris, Cody E., Wessel, Paige A., Tinius, Rachel A., Schafer, Mark A., Maples, Jill M.
• Format: Journal Article
• Language: English
• Published: United States Routledge 03.07.2019
• Subjects: Accelerometry - instrumentation; Accelerometry - standards; activity trackers; Adolescent; Adult; Adults; Body Weight; Body weight resistance training; Circuit-Based Exercise; Energy; Energy Metabolism; estimating energy expenditure; Exercise; Exercise Physiology; Fitness Trackers - standards; High-Intensity Interval Training; Humans; Measurement Equipment; Metabolism; Physical Activities; physical activity; Reproducibility of Results; Training; Young Adult; estimating energy expenditure; Body weight resistance training; activity trackers; physical activity
• ISSN: 0270-1367; 2168-3824
• DOI: 10.1080/02701367.2019.1603989

Purpose: The purpose of this study was to evaluate the agreement of five commercially available accelerometers in estimating energy expenditure while performing an acute bout of high-intensity functional training (HIFT). Methods: Participants (n = 47; average age: 28.5 ± 11.6 years) consisted of recreationally active, healthy adults. Each participant completed a session of HIFT: a 15-minute workout consisting of 12 repetitions each of air-squats, sit-ups, push-ups, lunges, pull-ups, steps-ups, and high-knees; performed circuit-style by completing as many rounds as possible. During this session, each participant wore the Cosmed K4b2 portable metabolic analyzer (PMA) and five different accelerometers (ActiGraph GT3X, Nike Fuelband, Fitbit One, Fitbit Charge HR, and Jawbone UP Move). Results: Four of the five activity trackers reported lower (p < .05) total EE values compared to the PMA during the acute bout of HIFT. The waist-mounted device (ActiGraph, 182.55 ± 37.93 kcal) was not significantly different from, and most closely estimated caloric expenditure compared to the PMA (144.99 ± 37.13 kcal) (p = .056). A repeated-measures ANOVA showed that all activity trackers were significantly different from the reference measure (PMA) (p < .05). Systematic relative agreement between the activity trackers was calculated, exhibiting a significant ICC = 0.426 (F [46,230] = 5.446 [p < .05]). Conclusion: The wrist- and hip-mounted activity trackers did not accurately assess energy expenditure during HIFT exercise. With the exception of the ActiGraph GT3X, the remaining four activity trackers showed inaccurate estimates of the amount of kilocalories expended during the HIFT exercise bout compared to the PMA.