How Many Steps/day Are Required to Meet the Physical Activity Guidelines?

Abstract

The importance of physical activity (PA) in health promotion is widely known throughout the world. According to typical PA guidelines, 150 min/week of moderate to vigorous physical activity (MVPA) in bouts lasting 10 minutes or more is recommended. Pedometers are widely used as a physical activity-monitoring tool. Translating current PA guidelines into a pedometer-based guideline could enhance the public health impact of PA interventions. PURPOSE: To determine a direct steps/day equivalent of 150 min/week accumulated MVPA, using concurrently detected triaxial accelerometer-defined step and PA data. METHODS: One hundred eight men (age: 49.3 ± 9.6 years, body mass index: 27.1 ± 3.7 kg/m2) wore triaxial accelerometers (Active style Pro, Omron Healthcare Co., Ltd) on the hip during waking hours (instructed to remove for swimming and bathing) for two consecutive weeks. The accelerometers were initialized to simultaneously measure both PA and steps in 60-second epochs. Participants who obtained no less than three full days of data, i.e., ≥ 10 hours/day, with at least one valid weekend day, were included in the analysis. MVPA was defined as an intensity of PA ≥ 3.0 metabolic equivalents. The receiver operating characteristic (ROC) curve was used to determine the cut-off value for steps/day meeting the PA guideline. RESULTS: Forty-one participants (38.0%) met the PA guideline. Analysis of the ROC curve suggests that 150 min/week of MVPA was equivalent to 8536 steps/day (area under curve: 0.85, 95% confidence interval: 0.78-0.92, sensitivity: 65.9%, specificity: 88.1%). CONCLUSIONS: Accumulating 8500 steps/day on every day of the week appears to be equivalent to obtaining 150 min of MVPA each week. This work was supported by Grant-in-Aid for Challenging Exploratory Research (23450429) and Grant-in-Aid for Research Activity Start-up (25882006) from Japan Society for the Promotion of Science.