The Validity of a Novel Low-Cost, Wearable Physical Activity Monitor in a Laboratory Setting

Introduction: Wearable physical activity monitors are popular and may provide a more accurate data than subjective methods. The present study assessed the validity of a novel, low-cost wearable physical activity monitor (Movband 3) relative to established measures. Methods: Participants (N = 19) completed four treadmill stages (1.5, 3.0, 4.0, 6.0 MPH) while wearing the Movband 3 and the validated Actigraph GT1M monitor. Oxygen consumption (VO2 ml/kg/min) and heart rate (beats/min) were recorded. The relationship between Movband data and established measures was assessed via Pearson’s correlations. Tests of agreement were performed for actual and Movband miles traveled. Results: There were large, positive, significant (p < 0.001) effect sizes for the associations between Movband counts and Actigraph counts (r = 0.72), VO2 (r = 0.59), and heart rate (r = 0.63). There was also a large, positive, significant (p < 0.001) association between actual and Movband miles (r = 0.97). However, the difference (Δ) between Movband and actual miles was greater than a null hypothesis of zero (∆ = 0.77 ± 0.45 miles or 31.8%, t = 7.4, p < 0.001). Conclusion: While there was evidence to support the validity of the Movband 3 for the assessment of physical activity intensity this device did not provide an accurate measure of miles traveled.