ABSTRACT
One of the most important metabolic functions of adipose tissue is the hydrolysis (lipolysis) of triacylglycerol (TG) and the subsequent release of non-esterified fatty acids (NEFAs) and glycerol. Because NEFAs are a significant fuel source for oxidation by working muscles, the hormonal regulation of this process during periods of excess energy expenditure is critical for the maintenance of fuel homeostasis, especially during long-term bouts of endurance exercise. Circulating levels of catecholamines and insulin, the main hormonal regulators of lipolysis, are altered during exercise to stimulate adipocyte lipolysis and provide additional NEFAs. Moreover, evidence
suggests that adipocytes adapt to acute and chronic increases in energy expenditure by enhancing their sensitivity to these hormonal regulators and increasing their capacity to mobilize NEFAs for generation of adenosine triphosphate (ATP) by exercising muscle.
