Exercise dose-response effects on quality of life and independent living in older adults.

PURPOSE: The purpose of this study was to determine if exercise operates in a dose-response fashion to influence well-being and to postpone dependency.
METHODS: A computer-assisted search was made by using the following key words: resistance training, strength training, function, exercise, elderly, quality of life, frailty, physical activity, independence, performance, aerobic training, mobility, well-being, and disability. Review articles and personal files were also used, and a critical review of research studies meeting the criteria described in the methods section of the article was conducted.
RESULTS: In large sample correlational studies and prospective longitudinal studies, researchers consistently report that measures of physical function in old adults are related to feelings of well-being, and that old adults who are physically active also report higher levels of well-being and physical function, but the results of randomized intervention studies of aerobic and/or resistive strength training do not always support this relationship. Even if changes in well-being and physical function were reported, no evidence was found that levels of intensity operated in a dose-response fashion to influence these changes. Research design problems included ineffective aerobic or strength training treatments, widely varying participation and effort of the research participants, and both treatment and physical function tests that were not appropriate for the physical status of the participants.
CONCLUSION: The most consistent results were that long-term physical activity is related to postponed disability and independent living in the oldest-old subjects. Even in individuals with chronic disease, systematic participation in physical activities enhances physical function.