PRT had a large positive effect on strength ( 41 trials , 1955 participants ) , but there was statistical heterogeneity that was not explained by differences in study quality , participant characteristics or the exercise program .
REVIEW ER 'S CONCLUSIONS PRT appears to be an effective intervention to increase strength in older people and has a positive effect on some functional limitations .
However , the effect of this intervention on more substantive outcomes such as measures of disability or HRQOL remains unclear .
BACKGROUND Muscle weakness in old age , is associated with physical disability and an increased risk of falls .
Progressive resistance strength ( PRT ) training exercises ( i.e. movements performed against a specific external force that is regularly increased during training ) are design ed to increase strength in older people .
OBJECTIVES To assess the effect of PRT on measures of physical disability , functional limitation and impairment in older people  , and identify adverse events .
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 had a large positive effect on strength ( 41 trials , 1955 participants ) , but there was statistical heterogeneity that was not explained by differences in study quality , participant characteristics or the exercise program .
REVIEW ER 'S CONCLUSIONS PRT appears to be an effective intervention to increase strength in older people and has a positive effect on some functional limitations .
However , the effect of this intervention on more substantive outcomes such as measures of disability or HRQOL remains unclear .
BACKGROUND Muscle weakness in old age , is associated with physical disability and an increased risk of falls .
Progressive resistance strength ( PRT ) training exercises ( i.e. movements performed against a specific external force that is regularly increased during training ) are design ed to increase strength in older people .
OBJECTIVES To assess the effect of PRT on measures of physical disability , functional limitation and impairment in older people  , and identify adverse events .