To determine the day-to-day variability of older adults’ physical activity, and to evaluate the accuracy of the 10,000-step goal for classifying whether older adults obtain 30 min of MVPA.
Ninety-one adults ages over 60 y wore a Yamax pedometer and Actigraph accelerometer for 7 days. Interday reliability was estimated via two-way ANOVA ICCs, and classification accuracy was evaluated via sensitivity, specificity, and ROC curve analysis.
Interday reliability was high; four of five outcome measures had a reliability of ≥.80 with only 2 days of data. The 10,000-step cut point had high accuracy for identifying days with less than 30 min of MVPA, but poor accuracy for identifying days with more than 30 min of MVPA.
Day-to-day variability in physical activity is lower in older adults than other age groups. The 10,000-step goal is inadequate for determining whether daily physical activity includes 30 min of MVPA in this population.
Rowe is with the Department of Sport, Culture and the Arts, University of Strathclyde Jordanhill Campus, 76 Southbrae Drive, Glasgow, UK; Kemble, Robinson, and Mahar are with the Activity Promotion Laboratory, Department of Exercise and Sport Science, East Carolina University, Greenville, NC.