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 .
Heavy-resistance training in older Scandinavian men and women: short- and long-term effects on arm and leg muscles.
The short- and long-term effects of heavy-resistance training ( 85 % of one-repetition maximum ( RM ) ) on elbow flexion and knee extension dynamic and isokinetic strength and on morphology in the biceps brachii and vastus lateralis muscles were evaluated during 1 year in 35 Sc and inavian men and women , aged 70 - 77 years , 12 of whom formed a control group . After the first 11 weeks of training ( n = 23 ; 3 times/week )  elbow flexion and knee extension dynamic strength ( 1 RM ) had increased [ mean + /- SD ] 49 % + /- 16 and 163 % + /- 75 , respectively , with no significant difference between men and women . For the following 27 weeks , strength was maintained with one training session per week ( n = 12 ) but dropped without training ( n = 11 ) . After the final 11 weeks of training ( n = 11 ; 3 times/week ) , strength had further increased 32 % + /- 16 in both the arm and the leg . Isokinetic strength measurements ( Cybex II ; 30 degrees/s ) revealed similar but smaller gains than for dynamic strength . Muscle biopsies ( n = 20 ) taken at the start and after the first 11 weeks of training showed a significant increase in the area of both type 1 and type 2 fibers in the biceps brachii muscle and a positive significant correlation between the percentage increase in the proportional area of type 2 fibers in the vastus lateralis muscle and the percentage increase in knee extension dynamic muscle strength . In conclusion , older Sc and inavian men and women have a high capacity both to improve and to maintain muscle strength , some of which is mediated through an adaptation in the muscle fiber type population
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 .