Influence of anaerobic and aerobic exercise on age-related pathways in skeletal muscle

Abstract

The aging process is characterized by the progressive loss of physiological stability, lower physical and cognitive reserve, and increased vulnerability to death. This progressive deterioration in organismal homeostasis is considered the underlying trigger of most chronic diseases like diabetes, neurodegenerative diseases and cancer. Experimental challenges that increase the rate of biological and cognitive decline are linked to accelerated aging while interventions that slow the aging process are accompanied by an extension in healthy lifespan (Lopez-Otin et al., 2013; Kennedy et al., 2014). Skeletal muscles perform several functions essential for locomotion and posture, and the loss of adequate mobility that occurs with aging causes the muscle to decrease its oxidative capacity and function. Gait speed represents an important integrative measure of muscle function and efficiency in the elderly (Peel et al., 2013) and its decline can be considered the best predictor of survival and health outcomes in humans (Perera et al., 2016). The age-associated decline in energy supply caused by mitochondrial dysfunction and/or reduction in the numbers of mitochondria adversely affects skeletal muscle function and homeostasis. One significant way to increase or preserve skeletal muscle quality and strength needed for healthy aging is through regular physical activity (Cartee et al., 2016). The present review addresses key facets of human aging and presents a summary of relevant metabolic sensors in skeletal muscle that coordinate the organismal response to exercise. We will explore various aspects of exercise that contribute to the regulation of metabolic pathways implicated in muscle strength and regeneration, as well as in mitochondria recycling and efficiency. The benefits of exercise as a universal therapeutic “pill” for healthy aging will also be discussed.