Effects of high-intensity strength training on multiple risk factors for osteoporotic fractures. A randomized controlled trial.
OBJECTIVE
To determine how multiple risk factors for osteoporotic fractures could be modified by high-intensity strength training exercises in postmenopausal women.


METHODS
Randomized controlled trial of 1-year duration.


METHODS
Exercise laboratory at Tufts University, Boston, Mass.


METHODS
Forty postmenopausal white women, 50 to 70 years of age, participated in the study; 39 women completed the study. The subjects were sedentary and estrogen-deplete.


METHODS
High-intensity strength training exercises 2 days per week using five different exercises (n = 20) vs untreated controls (n = 19).


METHODS
Dual energy x-ray absorptiometry for bone status, one repetition maximum for muscle strength, 24-hour urinary creatinine for muscle mass, and backward tandem walk for dynamic balance.


RESULTS
Femoral neck bone mineral density and lumbar spine bone mineral density increased by 0.005 +/- 0.039 g/cm2 (0.9% +/- 4.5%) (mean +/- SD) and 0.009 +/- 0.033 g/cm2 (1.0% +/- 3.6%), respectively, in the strength-trained women and decreased by -0.022 +/- 0.035 g/cm2 (-2.5% +/- 3.8%) and -0.019 +/- 0.035 g/cm2 (-1.8% +/- 3.5%), respectively, in the controls (P = .02 and .04). Total body bone mineral content was preserved in the strength-trained women (+2.0 +/- 68 g; 0.0% +/- 3.0%) and tended to decrease in the controls (-33+77 g; -1.2% +/- 3.4%, P = .12). Muscle mass, muscle strength, and dynamic balance increased in the strength-trained women and decreased in the controls (P = .03 to < .001).


CONCLUSIONS
High-intensity strength training exercises are an effective and feasible means to preserve bone density while improving muscle mass, strength, and balance in postmenopausal women.
Nelson
M E
ME
USDA Human Nutrition Research Center on Aging, Tufts University, Boston, MA 02111.
Fiatarone
M A
MA
Morganti
C M
CM
Trice
I
I
Greenberg
R A
RA
Evans
W J
WJ
D000368:Aged; D000704:Analysis of Variance; D015519:Bone Density; D003404:Creatinine / Q000652:urine; D005081:Exercise Therapy; D005260:Female; D050723:Fractures, Bone / Q000209:etiology* / Q000517:prevention & control*; D006728:Hormones / Q000097:blood; D006801:Humans; D008875:Middle Aged; D009132:Muscles / Q000502:physiology; D009747:Nutritional Physiological Phenomena; D015663:Osteoporosis, Postmenopausal / Q000150:complications* / Q000628:therapy*; D004856:Postural Balance; D012307:Risk Factors
D006728:Hormones; D003404:Creatinine