Purpose: The purpose of this study was to determine associations of the Yale Physical Activity Survey (YPAS) with the Stanford 7-d physical activity recall (PAR) and several physiologic measures, both cross-sectionally and longitudinally.
Methods: Participants were 59 individuals (45% African-American, 79% women) between the ages of 60 and 80 yr who were enrolled in a clinical trial. From the YPAS, total time in activity, estimated weekly energy expenditure, and indices of vigorous activity, leisurely walking, moving, standing, sitting, and an overall summary index were determined. From the PAR, daily energy expenditure, and hours spent in light, moderate, and hard/very hard activities were estimated. Physiologic measurements included estimated VO2max, resting pulse rate, and body mass index (BMI).
Results: Weekly energy expenditure, total time in activity, and the summary index correlated with daily energy expenditure at baseline (Spearman correlations = 0.37, 0.30, 0.33, respectively, Ps < 0.01) and time in moderate activity (r = 0.37, 0.29, 0.39, Ps < 0.01). The vigorous index was also significantly correlated with daily energy expenditure and time in light, moderate, and hard/very hard activity. The summary, moving, and standing indices correlated with VO2max (Ps < 0.05) and BMI (Ps < 0.05). Change in physical activity determined from the PAR correlated with change in most YPAS dimensions, although few correlations were statistically significant.
Conclusions: The global activities and the vigorous activity index determined from the YPAS correlated with corresponding measures of the PAR. The validity of the YPAS for light-intensity activities is less clear, although optimal validation measures for light-intensity activity are yet to be defined. The ability of the YPAS to detect change in physical activity shows some promise, but data from this study are insufficient to be conclusive.