Crucially, all of the above should be approached with a multitude of in/ex vivo; techniques, combining recent electrophysiological advances such as intramuscular and high‐density electromyography (iEMG, HD‐sEMG), and molecular biology markers of denervation–reinnervation such as alterations in gene expression, production of exercise‐induced myokines, and fiber type morphology.
CONCLUSIONS
A healthy neuromuscular system is paramount to maintaining ambulation into old age. Any compromise to the integrity of MUs, including, apoptosis of motor neurons, denervation–reinnervation, muscle fiber atrophy and shifts in fiber type, may reduce the functional capacity of MUs and subsequently affect the force output of skeletal muscles. If MU remodeling persists, and reaches a threshold whereby sarcopenia occurs, the risk of frailty, disability, and premature mortality is high. Evidence from masters athletes highlights the benefits of lifelong exercise in both endurance‐ and strength‐type exercises; however, clear mechanistic evidence is lacking. Finally, future work is required to investigate the mechanisms which precede neuromuscular remodeling. Identifying these aspects may help to develop therapeutic drugs for those who cannot exercise (i.e., bed‐bound, post hip fracture) or those who are not willing to engage in physical activity regimens.
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