Site specificity of regular health club exercise on muscle strength, fitness, and bone density in women aged 29 to 45 years.
OBJECTIVE
To determine the effect of regular exercise with use of stepper or skier machines on muscle strength, cardiovascular fitness, bone mineral density, and markers of bone turnover in women aged 29 to 45 years.


METHODS
We evaluated 14 women: 5 who used a stepper machine for at least 3 hours each week for 2 years, 4 who used a skier machine for at least 3 hours each week for 2 years, and 5 who did not exercise (controls). All women were healthy, had no history of disease or medication use known to affect bone metabolism, and had normal levels of estradiol-17beta. Differences between the exercise and control groups were analyzed with the Kruskal-Wallis test.


RESULTS
No significant differences were noted between the exercise groups and the control group with respect to age, height, total body bone mineral density, calcium intake, and metabolic bone markers. Significant differences were noted between the groups in body weight (stepper vs control, P=.03; skier vs control, P=.02), body mass index (stepper vs control, P=.03; skier vs control, P=.02), Physical Activity Score (stepper vs control, P=.009; skier vs control, P=.01), percentage body fat (stepper vs control, P=.03; skier vs control, P=.02), and maximum oxygen consumption (stepper vs control, P=.009; skier vs control, P=.009). Bilateral hip extensor strength was significantly stronger in the stepper group than in the skier group (P=.03). Grip strength was significantly stronger in the stepper group than in the skier group (right, P=.01; left, P=.049).


CONCLUSIONS
Although comparable health club exercises can contribute to fitness, their site-specific effect varies. Stepper machines are preferred over skier machines for improving hip extensor strength.
Sinaki
Mehrsheed
M
Department of Physical Medicine and Rehabilitation, Mayo Clinic College of Medicine, Rochester, Minn 55905, USA.
Canvin
Joseph C
JC
Phillips
Benjamin E
BE
Clarke
Bart L
BL
D000328:Adult; D015519:Bone Density; D016723:Bone Remodeling; D003430:Cross-Sectional Studies; D015444:Exercise; D005260:Female; D020446:Fitness Centers; D006801:Humans; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000502:physiology*; D010809:Physical Fitness; D010865:Pilot Projects; D012016:Reference Values; D013997:Time Factors; D016474:Weight-Bearing