Low-cost, consumer-grade physical activity monitors may provide a more accurate measure of physical activity than subjective methods (e.g., self-report) while being less expensive than research-grade accelerometers or other objective methods. This study assessed the validity of a consumer-grade monitor (Movband 3) to measure physical activity intensity during treadmill exercise against previously validated measures of physical activity intensity: accelerometer counts (Actigraph GT1M), VO2, heart rate, ratings of perceived exertion, and treadmill miles. This study also examined Movband 3 reliability. Participants (N = 19) completed four, ten-minute treadmill stages (1.5, 3.0, 4.0, 6.0 MPH) while wearing one Movband per wrist and the previously-validated Actigraph monitor. There were large, positive effect sizes for the associations between Movband moves and Actigraph counts (r = 0.72), VO2, (r = 0.59), heart rate (r = 0.63), and RPE (r = 0.65). There was also a small, positive effect size (r = 0.27) for the association between moves reported by the Movband device worn on the dominant wrist and the Movband device worn on the non-dominant wrist. The low-cost, consumer-grade Movband accelerometer appears to provide a valid and reliable assessment of physical activity behavior/intensity.
Physical activity monitors are a popular tool in the measurement of physical activity in the consumer market, but much of the existing validity evidence is lab-based. These monitors will typically be used by consumers outside of a lab setting. This study assessed the validity of a consumer-grade monitor (Movband 3) to measure physical activity intensity and behavior in a free-living setting against a previously validated measure of physical activity intensity (Actigraph GT1M). A separate aim was to assess the ability to the monitors to elicit changes in physical activity behavior. Participants (N = 16) wore the Movband and Actigraph devices simultaneously for a minimum of five hours per day across five days. Participants completed a 7-day Physical Activity Recall Questionnaire (PARQ) before and after wearing the monitors. There was a large, positive effect size for the association between Movband moves and Actigraph counts (r = 0.57). There was no significant difference (t = 1.323, p = 0.204) in total daily caloric expenditure from the seven-day Physical Activity Recall when the physical activity monitors were worn versus the previous week with no device. The low-cost, consumer-grade Movband accelerometer appears to provide a valid assessment of physical activity behavior/intensity in a free-living setting.