Aging is the progressive and inevitable process of bodily deterioration during adulthood. In skeletal muscle, primary aging causes defective mitochondrial energetics, and reduced muscle mass. Secondary aging refers to additional structural and
functional age-related changes caused by diseases and lifestyle factors. Exercise opposes deleterious effects of secondary aging.
Most individuals wish to be “forever young”, and do not experience the age-related changes. Unfortunately primary aging is unavoidable. There exist various stages along the continuum of primary aging. The quality of skeletal muscle of individuals in the age range between 65–75 years differs from the muscles of individuals over 75 years. It is possible to increase life span and quality of life by limiting secondary aging, respectively the deleterious structural and functional changes that are caused by diseases and environmental factors. Healthy lifestyle promotes well-being, minimizes disease development, and consequently secondary aging. In the third decade even most physically active people expierence decline in relative maximal oxygen consumption due to primary aging. Lifestyle modifications can both accelerate both slow this process.
Age-associated chronic basal inflammation compromises muscle mass and adaptability, but exercise training may exert an anti-inflammatory effect and turn back the clock of muscle ageing. Recently published article in Journal of Applied Physiology assessed basal and exercise-induced inflammation in three cohorts of men: young exercisers, old healthy non-exercisers and lifelong exercisers. The researchers measured their thighs for muscle mass, and took blood and muscle biopsies before and after a resistance exercise challenge. As expected, physical stress induced pro-inflamatory response and secretion of cytokines, but compared with non-exercisers lifelong exercise partially prevented this. The muscles of life-long exercisers in their 70s in all qualities were comparable to those of active 25-year-old participants. Regular exercise training protects against the aging-related changes responsible for development of insulin resistance. On the contrary, physical inactivity and sedentary behavior have a deleterious effect on human health that is comparable to smoking.
Muscle- aging is caused by changes in the muscle itself as well as changes in the central nervous system.
Sure, in this study, the benefits were obtained from those who had been active their whole life, but it is never to late for start.