INTRODUCTION: Optimal treatment and prevention of osteoporosis require modification of risk factors, particularly adequate physical activity in addition to attention to diet. A number of physical educational opinions are available to health care providers. This study examines whether regular exercise has the potential of positively affecting the aging process in Japanese adults with regard to bone strength.
METHOD: Bone strength measurements were taken from 199 subjects using an ultrasound method to measure speed of sound (SOS, m/sec). The subjects were composed of 78 males (aged 49.5 +/- 20.6) and 121 females (aged 48.9 +/- 17.5). They also answered a questionnaire about levels of physical activity (whether they exercised more than once a week, once a week, or less than once a week on average). SOS data for each gender was analyzed using analysis ANCOVA with level of physical activity as an independent variable and age in years as a covariate.
RESULTS: The average SOS (m/sec) of males is 1576 in the young and 1483 in the old, and for females the average is 1568 and1483, respectively. The results of ANCOVA made it clear that the physical activity level affected the SOS in the case of female subjects, although it did not affect the SOS in the case of male subjects. These data suggest that lifelong moderate exercise is associated with attenuation of the decline of SOS in females after being adjusted for age. However, the magnitude of the attenuation is significantly lower in males.