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 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 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 .