Ageing is a complex process involving many factors that interact with one another, including lifestyle behaviors and genetic factors.
Advancing age is associated with physiologic changes that result in reductions in functional capacity and altered body composition and with declines in physical activity volume and intensity. It is likely that a combination of genetic and lifestyle factors contribute to the wide Inter-individual variability seen in older adults.
There are scientific evidences supporting the fact that regular physical activity increases average life expectancy through its influence on chronic disease development even though individuals differ widely in how they age and in how they adapt to an exercise program.
However, according to the latest guidelines of the American College of Sports Medicine (ACSM), Aerobic Exercise and Resistance Exercise (Strength Training) can increase aerobic capacity and muscle strength, respectively, by 20%–30% or more in older adults, minimizing the physiological effects of an otherwise sedentary lifestyle and increase active life expectancy by limiting the development and progression of chronic disease and disabling conditions.
In the ACSM Position stand the strength of the evidence resulting from the literature analysis were categorize according to this scheme:
- Evidence Level A. Overwhelming evidence from Randomized Controlled Trials s and/or observational studies, which provides a consistent pattern of findings on the basis of substantial data.
- Evidence Level B. Strong evidence from a combination of Randomized Controlled Trials and/or observational studies but with some studies showing results that are inconsistent with the overall conclusion.
- Evidence Level C. Generally positive or suggestive evidence from a smaller number of observational studies and/or uncontrolled or nonrandomized trials.
- Evidence Level D. Panel consensus judgment that the strength of the evidence is insufficient to place it in categories A through C.
Here the major evidences resulting from the ACSM Position Stand related to different aspects of training:
Evidence category A. Regular physical activity increases average life expectancy through its influence on chronic disease development, through the mitigation of age-related biological changes and their associated effects on health and well-being, and through the preservation of functional capacity.
Evidence category B/C. Regular physical activity can favorably influence a broad range of physiological systems and may be a lifestyle factor that discriminates between those individuals who have and have not experienced successful aging.
Evidence category B. Vigorous, long-term participation in Aerobic Training is associated with elevated cardiovascular reserve and skeletal muscle adaptations that enable the aerobically trained older individual to sustain a submaximal exercise load with less cardiovascular stress and muscular fatigue than their untrained peers. Prolonged aerobic exercise also seems to slow the age-related accumulation of central body fat and is cardioprotective.
Evidence category A. Older adults can substantially increase their strength and muscular power after Resistance Training.
Evidence category B. Increases in Muscle Quality are similar between older and younger adults, and these improvements do not seem to be sex-specific.
(American College of Sports Medicine position stand. Exercise and physical activity for older adults. Chodzko-Zajko WJ, Proctor DN, Fiatarone Singh MA, Minson CT, Nigg CR, Salem GJ, Skinner JS. Med Sci Sports Exerc. 2009 Jul;41(7):1510-30)