INTRODUCTIONSkeletal muscle function is the most important element of a healthy and active life in older adults and is closely related to every kind of physical effort [1]. Despite the natural phenomenon of losing muscle mass and strength in the aging process, this has recently been recognized as a disease and has been defined as sarcopenia [2]. The reason for this is that muscle atrophy due to aging is part of several functional disorders, including decreased muscle strength and flexibility, vulnerability to injury, and delayed functional recovery [3][4][5]. Compared to young and middleaged adults, people aged 70-85 years old experience a 30% decrease in muscle mass [6].Resistance training has become a strategy to prevent muscle atrophy [7].It also improves physical function, muscle strength, and the ability to maintain muscle mass [8]. Recently, mechanism-based (power training, eccentric training, high intensity interval training, hybrid electrical stimulation training) interventions incorporated with age-related changes have been attempted in exercise interventions for older adults [9-12]. The age-
ORIGINAL ARTICLE
PURPOSE:Reduced muscular strength is a key player in loss of physical function and quality of life in older adults. It has been reported that eccentric training has positive effects on the preservation of eccentric strength, produces less delayed onset muscle soreness, and has a lower metabolic cost for older individuals. Therefore, the present study investigated the effects of eccentric-based training on skeletal muscle strength and physical function in older adults.
METHODS:Sixteen healthy older subjects (over the age of 65) participated either in eccentric training group (ETG, n=8) or in conventional resistance training group (CTG, n=8) twice a week for eight weeks. The ETG group performed motorized eccentric training, and the CTG group performed a leg press using air pressure. Physical function and muscular strength assessments were performed before and after 8 weeks. The primary outcomes for physical function included gait speed, stair climbing, and the chair stand test, and the secondary outcomes included muscle strength and power.
RESULTS:The ETG group demonstrated significant improvements in physical function (gait speed and stair climbing) and muscle strength (isokinetic strength and power in knee tests) (p<.05) compared to the CTG group after 8 weeks. There were no significant differences for chair stand test (p>.05) after 8 weeks.
CONCLUSIONS:Motorized eccentric-based training was more effective in improving muscle strength and physical function in aged individuals than conventional resistance training, which s suggests that eccentric training is may be more beneficial for older individuals to improve overall physical function.