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 .
Progressive strength training in sedentary, older African American women.
PURPOSE This study investigated effects of an 8-wk , low-frequency and low-volume , supervised , progressive strength training program emphasizing free weight , multijoint movements on the muscular power , strength , endurance , and flexibility of African American women 44 to 68 yr of age . METHODS Nineteen sedentary African American women were r and omly assigned to a  strength training ( ST ) only group ( N = 12 ; mean age , 51 yr ) or a  nonexercise control ( C ) group ( N = 7 ; mean age , 52 yr ) . Maximal power , strength , absolute endurance , and flexibility were assessed before and after training . Subjects trained 2 d x wk(-1 ) using free weight ( barbells and dumbbells ) and machine ( plate loaded ) exercises for two to three sets of 8 to 10 repetitions on both primary and assistance exercises . RESULTS Upper body power ( medicine ball put distance ) significantly increased statistically ( P = 0.002 ) , but gains possibly lacked practical significance because of measurement variation . Lower body power ( peak watts on bicycle ) experienced a small , nonsignificant increase in the ST group . Significant increases ( P = 0.000 ) in 1RM muscle strength occurred in the ST group ( leg press , + 99.8 % ; bench press , + 34.4 % ) . Absolute endurance significantly increased ( P = 0.000 ) in the ST group ( leg press repetitions to failure at 70 % pretest 1RM , + 221 % ; bench press repetitions to failure at 50 % pretest 1RM , + 112 % ) . Significant flexibility gains occurred in the ST group ( sit- and -reach test , + 8.2 % ; P = 0.017 ) . No significant changes occurred in power , strength , absolute endurance , or flexibility in the C group . CONCLUSION This study demonstrates that 8 wk of low-frequency , supervised , progressive strength training emphasizing free weight , multijoint movements can safely cause significant gains in muscle strength , absolute endurance , and flexibility in older African American 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 .