Pedometer-measured physical activity of adults with intellectual disability: predicting weekly step counts

Pedometers are objective, inexpensive, valid, and reliable measures of physical activity. The minimum number of days of pedometer monitoring needed to estimate average weekly step counts was investigated. Seven days of pedometer data were collected from 154 ambulatory men and women (ns = 88 and 66, respectively) with intellectual disability. Correlations between average weekly steps and 3-day combinations ranged from .80 to .94, and adjusted R(2) for 3 days of monitoring was .886. Results suggest that 3 days of pedometer wear is sufficient to predict average weekly steps among ambulatory adults with intellectual disability. This finding will allow researchers to reduce participant burden and study costs, may guide measurement procedures, and inform missing data protocols.