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 .
Large energetic adaptations of elderly muscle to resistance and endurance training.
This study determined the cellular energetic and structural adaptations of elderly muscle to exercise training .  Forty male and female subjects ( 69.2 + /- 0.6 yr ) were assigned to a control group or 6 mo of endurance ( ET ) or resistance training ( RT ) . We used magnetic resonance spectroscopy and imaging to characterize energetic properties and size of the quadriceps femoris muscle . The phosphocreatine and pH changes during exercise yielded the muscle oxidative properties , glycolytic ATP synthesis , and contractile ATP dem and . Muscle biopsies taken from the same site as the magnetic resonance measurements were used to determine myosin heavy chain isoforms , metabolite concentrations , and mitochondrial volume densities . The ET group showed changes in all energetic pathways : oxidative capacity ( + 31 % ) , contractile ATP dem and ( -21 % ) , and glycolytic ATP supply ( -56 % ) . The RT group had a large increase in oxidative capacity ( 57 % ) . Only the RT group exhibited change in structural properties : a rise in mitochondrial volume density ( 31 % ) and muscle size ( 10 % ) . These results demonstrate large energetic , but smaller structural , adaptations by elderly muscle with exercise training . The rise in oxidative properties with both ET and RT suggests that the aerobic pathway is particularly sensitive to exercise training in elderly muscle . Thus elderly muscle remains adaptable to chronic exercise , with large energetic changes accompanying both ET and RT
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 .