JEPonline Relative Contributions of Central and Peripheral Factors in Human Muscle Fatigue during Exercise: A Brief Review

Shei R-J, Mickleborough TD. Relative Contributions of Central and Peripheral Factors in Human Muscle Fatigue during Exercise: A Brief Review. JEPonline 2013;16(6):1-17. Exercise performance is limited by fatigue, which is characterized as central or peripheral depending on whether it develops proximal or distal to the neuromuscular junction. Both models account for detriments in the ability of muscles to generate force or do work. The peripheral model holds that fatigue is the result of limitations in muscle milieu (resulting from metabolite accumulation, phosphagen and substrate depletion) and changes in the contractile machinery of muscles. Conversely, the central model states that fatigue results from central factors such as impairment in motivation, neuromuscular transmission, motor unit recruitment, and motor cortex activation. A novel model of integrative central control (i.e., the central governor model, CGM) proposes both central and peripheral factors. While facets of the CGM explain the phenomena related to fatigue during exercise that neither the central model nor the peripheral model can, more experimental evidence is needed to refine and support it. Thus, it is clear that fatigue remains a poorly understood topic and a fertile area for future research.