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 a short-term strength training programme on lymphocyte subsets at rest in elderly humans
Abstract The effects of a short-term strength training programme on resting lymphocyte subsets and stress hormone concentrations were analysed in 32 elderly sedentary subjects . Out of these 32 subjects , 8 women and 8 men [ mean age 70.1 ( SEM 1.0 ) years ] were r and omly assigned to a 8-week strength training programme which consisted of three sets of eight repetitions at 80 % of one repetition maximum , for leg press , bilateral leg extension and seated chest press , 3 days a week . The remaining 8 women and 8 men [ mean age 70.5 ( SEM 0.9 ) years ] served as controls  . Absolute counts of lymphocyte subsets ( CD20 + , CD3 + , CD3+CD4 + , CD3+CD8 + , CD3−CD56+CD16 + ) were measured with a new technique combining fluorescent microspheres and flow cytometry . In the trained subjects , substantial increases in strength took place in one repetition maximum during the 8-week training period for leg press [ from means of 20.7 ( SEM 1.0 ) to 23.6 ( SEM 1.0 ) N · kg−1LBM ( lean body mass ) ] , chest press [ from means of 5.4 ( SEM 0.3 ) to 6.2 ( SEM 0.3 ) N · kg−1LBM ] and bilateral leg extension [ from means of 6.3 ( SEM 0.2 ) to 7.4 ( SEM 0.3 ) N · kg−1LBM ] movements . Baseline cortisol concentration ( P < 0.01 ) , CD20 + cell count ( P < 0.05 ) , CD3 + cell count ( P < 0.05 ) , and CD4 + cell count ( P < 0.01 ) decreased in both groups secondary to circannual variations between winter and summer . No significant effect of strength training on resting adrenaline , noradrenaline and cortisol concentrations or distributions of lymphocyte subsets at rest was observed . The main finding of this study was to demonstrate that 8-week is too short a duration for a strength training programme to modify counts of lymphocyte subsets at rest in elderly sedentary adults
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 .