Aging, Functional Capacity and Eccentric Exercise Training

ABSTRACT: Aging is a multi-factorial process that ultimately induces a decline in our physiological functioning, causing a decreased health-span, quality of life and independence for older adults. Exercise participation is seen as a way to reduce the impact of aging through maintenance of physiological parameters. Eccentric exercise is a model that can be employed with older adults, due to the muscle's ability to combine high muscle force production with a low energy cost. There may however be a risk of muscle damage before the muscle is able to adapt. The first part of this review describes the process of aging and how it reduces aerobic capacity, muscle strength and therefore functional mobility. The second part highlights eccentric exercise and the associated muscle damage, in addition to the repeated bout effect. The final section reviews eccentric exercise interventions that have been completed by older adults with a focus on the changes in functional mobility. In conclusion, eccentric endurance exercise is a potential training modality that can be applied to older adults for improving muscle strength, aerobic capacity and functional ability. However, further research is needed to assess the effects on aerobic capacity and the ideal prescription for eccentric endurance exercise. Key words: Eccentric exercise, functional ability, muscle strength, aerobic capacity, muscle damage As life-span is on the increase and the population of older adults (65+) continues to grow, the prevalence of chronic disease increases and health-span decreases. Due to the proportion of older adults expanding, it is important to understand how the aging process influences functional ability of individuals (i.e. 'the competence of an individual to have the physiological capacity to perform normal everyday activities safely and independently without undue fatigue') [1] and whether regular exercise is useful as a preventive measure for the decline in functional ability. The capacity to perform activities of daily living (ADL) is essential to a satisfactory health-related quality of life. The etiology of functional decline is complex, however, a primary contributor to this is sarcopenia -the agerelated loss of muscle mass and quality [2] -and a less efficient cardiovascular system The use of eccentric exercise training is an appealing non-conventional exercise model for older adults. Due to its reduced oxygen requirement lowering the metabolic demand, such an activity has the potential to address the age-related decline in functional abilit