Systematic Review of Progressive Resistance Strength Training in Older Adults

Functional assessment is an important part of the evaluation of elderly persons. We conducted this study to determine whether objective measures of physical function can predict subsequent disability in older persons. This prospective cohort study included men and women 71 years of age or older who were living in the community, who reported no disability in the activities of daily living, and who reported that they were able to walk one-half mile (0.8 km) and climb stairs without assistance. The subjects completed a short battery of physical-performance tests and participated in a follow-up interview four years later. The tests included an assessment of standing balance, a timed 8-ft (2.4-m) walk at a normal pace, and a timed test of five repetitions of rising from a chair and sitting down. Among the 1122 subjects who were not disabled at base line and who participated in the four-year follow-up, lower scores on the base-line performance tests were associated with a statistically significant, graduated increase in the frequency of disability in the activities of daily living and mobility-related disability at follow-up. After adjustment for age, sex, and the presence of chronic disease, those with the lowest scores on the performance tests were 4.2 to 4.9 times as likely to have disability at four years as those with the highest performance scores, and those with intermediate performance scores were 1.6 to 1.8 times as likely to have disability. Among nondisabled older persons living in the community, objective measures of lower-extremity function were highly predictive of subsequent disability. Measures of physical performance may identify older persons with a preclinical stage of disability who may benefit from interventions to prevent the development of frank disability.

Since falling is associated with serious morbidity among elderly people, we investigated whether the risk of falling could be reduced by modifying known risk factors. We studied 301 men and women living in the community who were at least 70 years of age and who had at least one of the following risk factors for falling: postural hypotension; use of sedatives; use of at least four prescription medications; and impairment in arm or leg strength or range of motion, balance, ability to move safely from bed to chair or to the bathtub or toilet (transfer skills), or gait. These subjects were given either a combination of adjustment in their medications, behavioral instructions, and exercise programs aimed at modifying their risk factors (intervention group, 153 subjects) or usual health care plus social visits (control group, 148 subjects). During one year of follow-up, 35 percent of the intervention group fell, as compared with 47 percent of the control group (P = 0.04). The adjusted incidence-rate ratio for falling in the intervention group as compared with the control group was 0.69 (95 percent confidence interval, 0.52 to 0.90). Among the subjects who had a particular risk factor at base line, a smaller percentage of those in the intervention group than of those in the control group still had the risk factor at the time of reassessment, as follows: at least four prescription medications, 63 percent versus 86 percent, P = 0.009; balance impairment, 21 percent versus 46 percent, P = 0.001; impairment in toilet-transfer skills, 49 percent versus 65 percent, P = 0.05; and gait impairment, 45 percent versus 62 percent, P = 0.07. The multiple-risk-factor intervention strategy resulted in a significant reduction in the risk of falling among elderly persons in the community. In addition, the proportion of persons who had the targeted risk factors for falling was reduced in the intervention group, as compared with the control group. Thus, risk-factor modification may partially explain the reduction in the risk of falling.