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 .
Effects of resistive and balance exercises on isokinetic strength in older persons.
OBJECTIVE To determine the safety and efficacy of 3 months of resistive training of multiple lower extremity muscle groups compared with balance training in persons over 75 years . DESIGN R and omized 3-month clinical trial . Subjects ( n = 110 , mean age 80 ) were r and omized to 4 groups in a 2 x 2 design ( control , resistive , balance , combined resistive/balance ) . INTERVENTIONS Resistive training involved knee extension and flexion , hip abduction and extension , and plantar and dorsiflexion using simple resistive machines and s and bags . Balance training consisted of exercises to improve postural control . The control group attended 5 health-related discussion sessions . MEASUREMENTS Summed isokinetic moments ( N m ) of 8 leg movements : hip , knee and ankle flexion/extension , and hip abduction/adduction . Secondary outcomes were gait velocity and chair rise time . MAIN RESULTS Summed peak moment increased in both resistive exercise-trained groups ( 13 % increase in the resistive group and 21 % in the combined training group , P < 0.001 ) . The effect of resistance training was significant ( MANOVA F = 21.1 , P < 0.001 ) , but balance training did not improve strength , and there was no interaction ( positive or negative ) between balance and resistive training . Maximal gait velocity and chair rise time did not improve . Eleven subjects ( 20 % ) had musculoskeletal complaints related to resistive training , but all were able to complete the program with modifications . CONCLUSION Resistive training using simple equipment is an effective and acceptable method to increase overall leg strength in older persons .  Resistive or balance training did not improve maximal gait velocity or chair rise time in this sample of relatively healthy older persons
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 .