Total and leisure-time walking among U.S. adults should every step count?

BACKGROUND: Although walking is a popular leisure-time activity, a substantial amount of total daily walking occurs in non-leisure contexts (i.e., occupation, transportation, and household work). Because non-leisure walking is not assessed by traditional leisure-time activity surveys, total walking among U.S. adults may be underestimated. This study describes walking estimates obtained from a measure of leisure-time activity and a specific measure of total walking in all contexts. METHODS: A national sample of adults (n=6626), selected by random-digit dialing, was surveyed between May 1999 and November 2000. Estimates of walking prevalence and of weekly time spent walking were examined from two separate modules: (1) an assessment restricted to leisure-time activity, and (2) an assessment of total walking. RESULTS: Walking prevalence based on the total walking module was nearly double that based on the leisure-time module (81% vs 43%, respectively). The median weekly minutes of walking also nearly doubled using the total walking module (239 vs 130 minutes, respectively). Among those with jobs involving substantial walking, median weekly walking minutes were more than three times greater with the total walking module (476 vs 130 minutes, respectively). CONCLUSIONS: U.S. adults, particularly those with jobs involving walking, do a substantial amount of walking not captured by traditional leisure-time activity surveys. This may affect the appropriate targeting of physical activity interventions, as well as the evaluation of the effectiveness of physical activity promotions and policies. However, further characterization of non-leisure walking is needed to determine its contribution to health and meeting physical activity guidelines.