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 .
A longitudinal trial of weight training in the elderly: continued improvements in year 2.
We conducted a 2-year ( 42 weeks of consecutive training in each year , separated by 10 weeks of testing and vacation time ) r and omized , controlled trial of weight training in 142 healthy male and female subjects , aged 60 to 80 years . Measurements included dynamic strength , symptom-limited endurance in cycling , treadmill walking and stair climbing , muscle size , and bone mineral density and content of the lumbar spine and whole body .  One hundred and thirteen subjects completed the study ( 57 exercise , 56 control ) , with a mean attendance of 85 % among the exercisers . Muscle strength was unchanged in the control subjects but increased ( collapsed across age and gender ) from 32 % ( leg press ) to 90 % ( military press ) in the exercisers . Symptom-limited endurance in cycling , treadmill walking , and stair climbing increased in the exercisers by ( mean + /- SE ) 6.2 + /- 0.8 % , 29.2 + /- 7.3 % , and 57 + /- 12 % , respectively ; the only change in the controls was an unanticipated 33 % increase in stair climbing performance during the first year . These values were unchanged in the controls . Cross-sectional area of the knee extensors increased by 8.7 + /- 0.9 % in the trained subjects and was unchanged in controls . Measures of whole body , lumbar spine bone mineral density , and lumbar spine bone mineral content were unchanged in the exercisers , but whole body bone mineral content decreased by 1 % . In contrast , there were small increases ( < 4.0 % ) in bone mineral density among the controls . Long-term weight training proved to be a safe and well-tolerated mode of exercise for the elderly . Increased strength was associated with muscle hypertrophy in each year , and with increased endurance in cycling , walking , and stair climbing . There were no changes in bone mineral density but a small reduction in whole body bone mineral content
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 .