This study indicates that daily physical activity of MHD patients, measured by the activity monitor and physical performance were substantially reduced compared with normal adults. Our accelerometer measured daily physical activity and the three physical performance tests appear to be reliable and reproducible [21, 23]. The 6-MWT and sit-to-stand test rather objectively monitor progress after exercise training in MHD patients [23]. However, after adjustment for age, gender, and diabetes, our study demonstrated a significant association only between daily physical activity and 6-MWT but not sit-to stand or stair climbing (Table 4). Maximum activity and adjusted activity human activity profile scores correlated with daily physical activity in unadjusted but not adjusted analyses. However, the human activity profile maximum activity and adjusted activity scores were highly significantly correlated, both before and after adjustment, with each of the three physical performance tests (Table 4, Figs. 3 and 4). These findings support the contention that the human activity profile gives a more reliable assessment of physical performance or exercise capability than it does of daily physical activity [20, 24].