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 .
Exercise effects on bone mass in postmenopausal women are site-specific and load-dependent.
It is considered that skeletal mass in humans may respond to loading or the number of loading cycles . The aim of this study was to examine the effect of a 1 year progressive resistance training program on the bone mass of 56 postmenopausal women . Assignment was by block r and omization to one of two resistance training groups : a strength trained group ( 3 x 8 repetition maximum ) or an endurance group ( 3 x 20 repetition maximum ) . The resistance exercises were selected to stress the ipsilateral forearm and hip region . The exercising side was r and omly assigned with one side exercised while the alternate side acted as the nonexercise control .  Bone mineral density ( BMD ) was measured every 3 months at the radial forearm and four hip sites using the Hologic QDR 2000 bone densitometer . A linear regression function was fitted for each individual 's bone density results , and the slope was compared for the exercise and control side using paired t-tests . The bone mass increase with the strength regimen was significantly greater at the trochanteric hip site ( control -0.6 + /- 2.2 % , exercise 1.7 + /- 4.1 % , p < 0.01 ) , at the intertrochanteric hip site ( control -0.1 + /- 2.1 % , exercise 1.5 + /- 3.0 % , p < 0.05 ) , Ward 's triangle ( control 0.8 + /- 5.2 % , exercise 2.3 + /- 4.0 % , p < 0.05 ) , and at the ultradistal radial site ( control -1.4 + /- 2.3 % , exercise 2.4 + /- 4.3 % , p < 0.01 ) . There was no significant increase in BMD with the endurance regimen except at the radius midsite ( control -1.0 + /- 2.3 % , exercise 0.1 + /- 1.4 % , p < 0.01 ) . In both the endurance and the strength group , muscle strength , tested by a one-repetition maximum ( 1RM ) test , increased significantly for all 10 exercises ( p < 0.01 ) and to a similar degree in the two groups . In the strength group but not the endurance group there were significant correlations between the slope of the change in BMD and the percentage increase in strength as follows : trochanter with leg press ; intertrochanter with leg press ( p < 0.05 ) ; and Ward 's triangle with hip extension and hip adduction ( p < 0.05 ) . Thus these results support the notion of a site-specific response of bone to maximal loading from resistance exercise in that although the trochanter and intertrochanter bone density was elevated by the resistance exercises undertaken , there was no effect on the femoral neck value . Postmenopausal bone mass can be significantly increased by a strength regimen that uses high-load low repetitions but not by an endurance regimen that uses low-load high repetitions . We conclude that the peak load is more important than the number of loading cycles in increasing bone mass in early postmenopausal women
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 .