Descriptive epidemiology of pedometer-determined physical activity

Purpose: The dual purposes of this study were: 1) to provide preliminary descriptive epidemiology data representing pedometer-determined physical activity (PA) and 2) to explore sources of intra-individual variability in steps per day. Methods: All participants (76 males, age = 48.4 ± 16.3 yr, body mass index (BMI) = 27.1 ± 5.1 kg·m^-2; 133 females, age = 47.4 ± 17.5 yr, BMI = 26.9 ± 5.7 kg·m^-2) resided in Sumter County, SC, and were recruited by telephone to receive a mailed kit to self-monitor PA for 1 wk. Statistical analyses compared mean steps per day between sexes, races, age groups, education and income levels, and BMI categories. Mean steps per day were also compared between: 1) weekdays versus weekend days, 2) workdays versus nonworkdays, and 3) days of sport/exercise versus no participation. Results: The entire sample took 5931 ± 3664 steps-d^-1 (males = 7192 ± 3596 vs females = 5210 ± 3518 steps·d^-1, t = 7.88, P < 0.0001). Significant differences were also indicated by race, age, education, income, and BMI. In addition, weekdays were significantly higher than weekend days, workdays were higher than nonworkdays, and sport/exercise days were higher than nonsport/exercise days. Conclusions: The large standard deviations reflect a wide distribution of ambulatory behavior. Regardless, important differences are still evident by demographic characteristics, BMI categories, day of the week, and reported engagement in work or sport/exercise.