Dietary Cholesterol Affects Skeletal Muscle Protein Synthesis Following Acute Resistance Exercise

Abstract

We have previously shown that high cholesterol (CL) intake resulted in greater lean mass gains in elderly men and women after 12 weeks of resistance training. However, little is known about the effects of CL on protein synthesis rates in skeletal muscle. We examined the effects of CL consumption on muscle protein synthesis in response to acute bouts of high intensity resistance exercise (RE).Two groups of 20–28 year old, healthy, untrained adults underwent 10 days of either high CL (HC: 14mg/kg lean/day, ~800mg/day, n=8) or low CL (LC: 3.5mg/kg lean/day, <200mg/day, n=7) diet followed by acute bouts of high intensity unilateral leg exercises (leg press & extension: 5 sets, reps to failure, 85% of max strength, emphasis on eccentric contraction) where one leg was exercised while the other leg served as the non‐exercise control. Biopsies were taken from vastus lateralis muscle 22h after exercise and cumulative myofibrillar protein synthesis (FSR) was measured using 2H2O as a tracer.A significant difference in FSR (relative to control) was observed between the groups (HC: 94.6±23% vs. LC: −65.4±25%, p<0.01) with ANCOVA analysis (covariates: exercise history, lean mass, & degree of muscle soreness after RE). Our data suggest that CL may affect the anabolic response to RE possibly through its effect on membrane stability, inflammatory response, and lipid rafts/cell signaling.