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 .
Knee extension strength and walking speed in relation to quadriceps muscle composition and training in elderly women.
Knee extension strength , walking speed , quadriceps muscle mass and composition of the muscle compartment were studied in 66 to 85-year-old female athletes and controls .  Maximal voluntary knee extension force , force/body mass , extension torque , torque/body mass and walking speed were higher for the athletes than the controls . A muscle index indicating intramuscular fat and connective tissue measured using ultrasonography was lower for the athletes than the controls . There were no differences between the study groups in knee extension force related either to cross-sectional area ( CSA ) or lean tissue area ( CSAL ) of the quadriceps . Within the subgroups , there was no significant correlation between knee extension torque and CSA or CSAL of the same muscle . In the athletes high knee extension torque/body mass was related to a low muscle index and high walking speed to a low relative proportion of fat in the muscle . The muscle index was lower the more kilometers trained during the preceding year . In the controls high knee extension torque/body mass and high walking speed were related to a low relative proportion of fat . Knee extension torque and walking speed were higher the more kilometers walked during the preceding year . The results indicate that elderly female athletes have superior muscle performance compared to their age-peers . Performance in a maximal isometric strength test in elderly women is not clearly related to muscle mass . However , to some extent it is related to the composition of the same muscle , especially the degree to which fat is infiltrated into the muscle
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 .