Evaluation of Step-Counting Interventions Differing on Intensity Messages.

Abstract

Step-counting interventions with discrepant intensity emphases may elicit different effects. A total of 120 sedentary/low-active, postmenopausal women were randomly assigned to one of the following 3 groups: (1)10,000steps per day (with no emphasis on walking intensity/speed/cadence; basic intervention, 49 completers), (2)10,000steps per day and at least 30minutes in moderate intensity (ie,at a cadence of at least 100steps per minute; enhanced intervention, 47 completers), or (3)a control group (19 completers). NL-1000-determined steps and active minutes (a device-specific indicator of time at moderate+ intensity) were collected as process variables during the 12-week intervention. Outcome variables included systolic and diastolic blood pressure, anthropometric measurements, fasting blood glucose and insulin, flow-mediated dilation, gait speed, and ActiGraph GT3X+-determined physical activity and sedentary behavior. The "basic group" increased 5173 to 9602steps per day and 9.2 to 30.2 active minutes per day. The "enhanced group" similarly increased 5061 to 10,508steps per day and 8.7 to 38.8 active minutes per day. The only significant change over time for clinical variables was body mass index. Interventions that use simple step-counters can achieve elevated volume and intensity of daily physical activity, regardless of emphasis on intensity. Despite this, few clinical outcomes were apparent in this sample of postmenopausal women with generally normal or controlled hypertension.