PRT results in improvements to muscle strength and some aspects of functional limitation , such as gait speed , in older adults .
However , based on current data , the effect of PRT on physical disability remains unclear .
Further , due to the poor reporting of adverse events in trials , it is difficult to evaluate the risks associated with PRT
BACKGROUND The aim of this systematic review was to quantify the effectiveness of progressive resistance strength training ( PRT ) to reduce  physical disability in older people .
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 . DESIGN R and omized controlled trial of 1-year duration . SETTING Exercise laboratory at Tufts University , Boston , Mass. POPULATION 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 . INTERVENTIONS High-intensity strength training exercises 2 days per week using five different exercises ( n = 20 ) vs untreated controls ( n = 19 ) . MAIN OUTCOME MEASURES Dual energy x-ray absorptiometry for bone status , one repetition maximum for muscle strength , 24-hour urinary creatinine for muscle mass , and backward t and em 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
PRT results in improvements to muscle strength and some aspects of functional limitation , such as gait speed , in older adults .
However , based on current data , the effect of PRT on physical disability remains unclear .
Further , due to the poor reporting of adverse events in trials , it is difficult to evaluate the risks associated with PRT
BACKGROUND The aim of this systematic review was to quantify the effectiveness of progressive resistance strength training ( PRT ) to reduce  physical disability in older people .