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 .
IGF-1 bioavailability is increased by resistance training in older women with low bone mineral density
We investigated if long-term resistance training would increase insulin-like growth factor-1 ( IGF-1 ) bioavailabilty at rest in older women ( 68+/-1 years ) with low bone mineral density .  IGF-1 levels were significantly lower ( P<0.05 ) , and insulin-like growth factor binding proteins -1 and -3 ( IGFBP-1 and IGFBP-3 ) significantly higher than an age-matched healthy normal group . Resistance training result ed in significant ( P<0.05 ) increases in repetition maximums across all exercises ( range 41 - 78 % ) . Resting IGF-1 levels were significantly ( P<0.05 ) elevated ( 70 % ) by the resistance training whereas no significant changes occurred in IGFBP-1 and IGFBP-3 levels . IGFBP-1/IGF-1 and IGFBP-3/IGF-1 ratios were significantly decreased ( approximately - 50 % ) as a result of resistance training ( P<0.05 ) . Thus , IGF-1 bioavailability was increased as a result of resistance training induced increases in IGF-1 levels in older women with low bone mineral density . These alterations in the IGF-1 system may be contributing to the significant strength gain observed with the resistance training in this 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 .