The role of circular RNAs in mediating the protective effects of exercise against muscle degeneration and aging.

A newly identified specific category of non-coding RNA (ncRNA), circRNAs, is drawing interest for their role in controlling several biological processes including muscle regeneration, aging, and adaptation to physical activity. Unlike linear RNAs, circRNAs are very stable and can have long-lasting regulatory impact since they create a covalently closed loop structure. Emerging evidence indicates that circRNAs play a pivotal role in skeletal muscle biology by regulating myogenesis, satellite cell activation, protein synthesis, and cellular senescence-processes significantly influenced by aging. These molecules are crucial for muscle function and regeneration, acting as microRNA sponges, interacting with RNA-binding proteins, and modulating gene expression and translation. Exercise-especially resistance and endurance training-has been shown to change circRNA expression in skeletal muscle, therefore possibly reducing age-related muscle loss and improving regenerative capacity. Though encouraging, much of the circRNA in muscle biology research is still in its early stages, with few functional studies and varying outcomes across various species and exercise models. Moreover, the exact ways circRNAs affect muscular adaptation to exercise and stop aging-related degeneration are still not completely known. This review addresses the existing knowledge gaps regarding the potential therapeutic applications of circRNAs in combating muscle degeneration and sarcopenia, as well as their role in muscle health and aging.