Quantitative ultrasound (QUS) parameters of the calcaneus and bone resorption markers predict osteoporotic fractures. High levels of physical activity have positive effects on bone health. The purpose of this cross-sectional study was to investigate the effects of daily walking activity (number of steps taken), as an outcome of physical activity, on QUS parameters of the calcaneus and urinary deoxypyridinoline (DPD) in elderly Japanese women. The subjects were 113 postmenopausal women aged 60-85 years. The speed of sound (SOS), broadband ultrasound attenuation (BUA), and the stiffness index (Stiffness) of the calcaneus were measured with A-1000 (GE-Lunar, USA). Spot urine samples were collected between 09:00 and 10:00, and the levels of urinary DPD were measured. The subjects were instructed to wear a pedometer during waking hours for 7 consecutive days. In univariate analyses, steps/day significantly decreased with aging (rϭϪ0.306, pϽ0.001). Steps/day showed significant positive correlations with SOS (rϭ0.252, pϽ0.01) and Stiffness (rϭ0.258, pϽ0.01). There was a significant decrease in DPD with steps/day (rϭϪ0.262, pϽ0.01). These effects of walking on QUS parameters and DPD remained significant after adjustment for confounding factors by multiple regression analyses. We conclude that high levels of walking activity may be effective in both maintaining the levels of QUS parameters and reducing bone resorption, and hence preserve bone health in elderly women. J Physiol Anthropol 27 (6) Huopio et al., 2004;Lee et al., 2002;Miller et al., 2002). In addition, high levels of bone turnover markers are related to an increased risk of osteoporotic fracture (Garnero et al., 1996(Garnero et al., , 2000. Krieg et al. (2006) reported that combining a bone resorption marker with a QUS parameter improves the prediction accuracy for patients at a high risk of fracture. Therefore, maintaining high QUS parameters and low levels in bone resorption markers could help in the prevention of osteoporotic fractures in elderly women.A (Iwamoto et al., 2002;Welsh and Rutherford, 1996;Woitge et al., 1998;Yamazaki et al., 2004) indicated that increased physical activity is effective in reducing the levels of bone resorption markers. Hoshino et al. (1996) reported that postmenopausal golf caddies had both higher QUS parameters and lower levels in bone resorption markers compared to sedentary controls. However, golf caddies are specific subjects with very high levels of occupational physical activity (they walk 5 miles a day and work 3 days a week for 2-20 years (Hoshino et al., 1996)), and no study has been carried out to investigate the associations of physical activity with both QUS parameters and bone resorption markers among the general elderly population.In most of the studies mentioned above, questionnaire-based assessments of physical activity were performed. As an alternative to this assessment, pedometers are a reliable way to monitor physical activity in healthy older adults without gait disorders (Cyarto et al.,...