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 resistance training on regional and total bone mineral density in premenopausal women: a randomized prospective study.
This study was design ed to assess the effects of 18 months of resistance exercise on regional and total bone mineral density ( BMD ) and soft tissue lean mass ( STL ) in premenopausal women aged 28 - 39 r and omly assigned to an exercise or control group .  Twenty-two exercise and 34 control subjects completed the 18-month training study . All subjects were previously inactive and untrained women . Initial , 5- , 12- and 18-month assessment s were made of total and regional BMD and total and regional STL using dual energy X-ray absorptiometry . All subjects consumed a 500 mg/day elemental calcium supplement throughout the study . Initial Ca intake without supplement averaged 1,023 mg/day in total sample . Serum levels of bone osteocalcin and dietary assessment s using 12 r and omly assigned days of diet records were also completed . Muscular strength was assessed from both 1 repetition maximum ( RM ) testing of 10 weightlifting exercises and by peak torque for hip abduction/adduction and knee extension/flexion . Training increased strength by 58.1 % based on 1 RM testing and by 33.8 % based on isokinetic testing at 18 months versus baseline . BMD increased significantly above baseline at the lumbar spine for the exercise group at 5 months ( 2.8 % ) , 12 months ( 2.3 % ) , and 18 months ( 1.9 % ) as compared with controls . Femur trochanter BMD increased significantly ( p < 0.05 ) in the exercise group at 12 months ( 1.8 % ) and 18 months ( 2.0 % ) but not at 5 months ( 0.7 % ) as compared with controls . No changes in total BMD , arm BMD , or leg BMD were found . There was a 20 % increase in BGP in the exercise group as compared with controls at 5 months and this difference was maintained throughout the study . For STL , significant increases for total , arm , and leg were found at 5 , 12 , and 18 months for the exercise group versus control ranging from 1 - 6 % over baseline . These results support the use of strength training for increasing STL and muscular strength with smaller but significant regional increases in BMD in the premenopausal population
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 .