Validation of four smartwatches in energy expenditure and heart rate assessment during exergaming

Objective: Validated the Apple Watch (AW), Fitbit Surge HR (FS), TomTom Multisport Cardio Watch (TT), and Microsoft Band (MB) in energy expenditure (EE), average heart rate (HR), and peak HR assessment during exergaming. Materials and Methods: Twenty-one college students participated in this study in Spring 2016. A 20-minute boxing session was completed on the Nintendo^® Wii™. The AW and TT were placed on the left wrist and the FS and MB on the right. Each smartwatches' EE and HR data were compared with identical data provided by ActiGraph GT3X+-Bluetooth accelerometers and an associated ActiGraph HR strap. Results: Initial agreement was observed between the ActiGraph and: FS and TT EE (r = 0.62-0.69); AW, FS, and TT average HR (r = 0.47-0.74); and all smartwatches' peak HR (r = 0.59-0.65). However, post hoc comparisons indicated differences between the ActiGraph and: FS and TT EE measurements (P < 0.01) and MB average/peak HR measurements (P < 0.01). Low measurement bias/adequate precision observed for most smartwatches versus ActiGraph. Conclusions: Observations indicated smartwatch average/peak HR measurements as moderately valid. Smartwatch EE measurements were less valid.