C. Snow-Harter

Exercise and Its Relationship to Bone Mass and Cardiovascular Function

Hypokinetic disease, defined as low physical activity or disuse, has been associated with a number of chronic diseases in the elderly, particularly cardiovascular diseases and, more recently, osteoporosis. Physical activity is considered to be an important factor in the etiology of these degenerative diseases. Although there is a paucity of data in the area of exercise among postmenopausal women, an increasing number of investigators are beginning to study exercise and the older woman. The intent of this chapter is to review recent literature that has examined the relationship of exercise to bone mass and cardiovascular function, as well as to offer advice relative to exercise prescription in postmenopausal women.

Muscle Hypertrophy Response To Resistance Training in Older Women

We conducted a 12-wk resistance training program in elderly women [mean age 69 +/- 1.0 (SE) yr] to determine whether increases in muscle strength are associated with changes in cross-sectional fiber area of the vastus lateralis muscle. Twenty-seven healthy women were randomly assigned to either a control or exercise group. The program was satisfactorily completed and adequate biopsy material obtained from 6 controls and 13 exercisers. After initial testing of baseline maximal strength, exercisers began a training regimen consisting of seven exercises that stressed primary muscle groups of the lower extremities. No active intervention was prescribed for the controls. Increases in muscle strength of the exercising subjects were significant compared with baseline values (28-115%) in all muscle groups. No significant strength changes were observed in the controls. Cross-sectional area of type II muscle fibers significantly increased in the exercisers (20.1 +/- 6.8%, P = 0.02) compared with baseline. In contrast, no significant change in type II fiber area was observed in the controls. No significant changes in type I fiber area were found in either group. We conclude that a program of resistance exercise can be safely carried out by elderly women, such a program significantly increases muscle strength, and such gains are due, at least in part, to muscle hypertrophy.