Endurance exercise training up-regulates lipolytic proteins and reduces triglyceride content in skeletal muscle of obese subjects

Abstract

Context: Skeletal muscle lipase and intramyocellular triglyceride (IMTG) play a role in obesityrelated metabolic disorders. Objectives: The aim of the present study was to investigate the impact of 8 weeks of endurance exercise training on IMTG content and lipolytic proteins in obese male subjects. Design and Volunteers: Ten obese subjects completed an 8-week supervised endurance exercise training intervention in which vastus lateralis muscle biopsy samples were collected before and after training. Main Outcome Measures: Clinical characteristics and ex vivo substrate oxidation rates were measured pre-and posttraining. Skeletal muscle lipid content and lipolytic protein expression were also investigated. Results: Our data show that exercise training reduced IMTG content by42%(P < .0001). Conclusions: Endurance exercise training coordinately up-regulates fat oxidative capacity and lipolytic protein expression in skeletal muscle of obese subjects. This physiological adaptation probably favors fat oxidation and may alleviate the lipotoxic lipid pressure in skeletal muscle. Enhancement of IMTG turnover may be required for the beneficial metabolic effects of exercise in obesity. © 2013 by The Endocrine Society.