Objective: The aim of this study was to investigate the relationship between functional capacity, muscle function, and daily step count in postmenopausal women.
Methods: Fifty-seven postmenopausal women aged 50 to 70 years were recruited. Body composition (body weight, body mass index, fat mass, and skeletal muscle mass), energetic metabolism (maximal oxygen consumption, total energy expenditure, daily step count), and functional capacity (muscle strength, muscle quality, chair stand, balance and alternate step tests) were measured. Women were divided into three groups (sedentary [n = 19], <7,500 steps; moderately active [n = 20], 7,500-10,000 steps; active [n = 18], >10,000 steps).
Results: A higher number of steps per day was associated with higher maximal oxygen consumption (mL/min per kg; P = 0.001) and total energy expenditure (P = 0.004) as well as lower body weight (P = 0.035) and fat mass (P = 0.048). Surprisingly, no differences for skeletal muscle mass, muscle strength, muscle quality, and functional capacity were observed between the groups, although this could have been because of the small sample size.
Conclusions: A daily amount of 10,000 steps seems to be associated with better body composition and higher cardiovascular functions. However, neither functional capacity nor muscle functions seem to be related to the daily amount of steps in postmenopausal women. Further prospective studies are needed to confirm our preliminary results because cross-sectional study designs do not permit the understanding of temporal relations.