Serious adverse events were rare , and no serious events were reported to be directly related to the exercise programme .
This review provides evidence that PRT is an effective intervention for improving physical functioning in  older people , including improving strength and the performance of some simple and complex activities .
BACKGROUND Muscle weakness in old age is associated with physical function decline .
Progressive resistance strength training ( PRT ) exercises are design ed to increase strength .
OBJECTIVES To assess the effects of PRT on older people and identify adverse events .
Muscle strength and fiber adaptations to a year-long resistance training program in elderly men and women.
BACKGROUND To study the effects of resistance training on muscle strength and size in older people , we enrolled 8 men and 17 women ( mean age 68.2 + /- 1 SEM ) into a one-year exercise trial . METHODS Subjects were r and omly assigned to exercise or control groups . Muscle biopsies were obtained from 11 subjects ( 8 exercisers/3 controls ) at baseline and after 15 weeks ; exercisers underwent another biopsy at 30 weeks . After testing maximum strength using the 1-RM method , the exercisers began a 12-exercise circuit ( 3 sets of 8 repetitions at 75 % of 1-RM ) , 3 times a week . The controls repeated the strength testing every 15 weeks . They were asked to continue usual activities and not to start any exercise program . RESULTS With exercise , muscle strength increased , average increases ranging from 30 % ( hip extensors ) to 97 % ( hip flexors ) . Strength increased rapidly over 3 months , then plateaued for the duration of the experiment . No strength changes were observed in sedentary controls . Cross-sectional area of type 1 muscle fibers increased in exercisers by 15 weeks ( 29.4 + /- 1 % , p < .02 ) and after 30 weeks ( 58.5 + /- 13.7 % , p < .002 ) compared to baseline . Type 2 fiber area did not change at 15 weeks , but increased by 30 weeks of training ( 66.6 + /- 9.5 % , p < .0002 ) . CONCLUSIONS These results suggest that prolonged moderate to high intensity resistance training may be carried out by healthy older adults with reasonable compliance , and that such training leads to sustained increases in muscle strength . These improvements are rapidly achieved and are accompanied by hypertrophy of both type 1 and type 2 muscle fibers
Serious adverse events were rare , and no serious events were reported to be directly related to the exercise programme .
This review provides evidence that PRT is an effective intervention for improving physical functioning in  older people , including improving strength and the performance of some simple and complex activities .
BACKGROUND Muscle weakness in old age is associated with physical function decline .
Progressive resistance strength training ( PRT ) exercises are design ed to increase strength .
OBJECTIVES To assess the effects of PRT on older people and identify adverse events .