Skeletal Muscle and Cardiovascular Health.

Cholesterol and triglycerides (TG) are major blood lipids. Cholesterol is essential for proper cell membrane development and is a vital substance for bile acids, steroid hormones, and vitamin D. TG is the major carrier of energy-containing fatty acids. These lipids are not soluble in aqueous body fluids and must bind to proteins forming lipoproteins in order to transport these lipids around the cardiovascular system and into body tissues. Unfortunately, elevated blood cholesterol and TG levels remain major United States Public Health problems. Genetics, diet, exercise, and physical activity (PA) affect blood and tissue lipids and lipoproteins. Peripheral tissues, especially muscle, and the liver, function in maintaining proper blood and tissue lipid and lipoprotein levels. In 1999, the World Health Organization published the first criteria for metabolic syndrome (MetSyn), but in 2001 the National Cholesterol Education Program's Adult Treatment Panel III published the widely used MetSyn criteria. For MetSyn factors, optimal benefits and improved muscle and liver function are obtained when aerobic exercise is completed in the upper PA range of the recommendations. Resistance training is effective in affecting some MetSyn factors. Non-alcoholic fatty liver disease (NAFLD) is the accumulation of liver fat not related to alcohol consumption. Modifying diet, achieving appropriate exercise/PA levels, and maintaining proper weight are the mainstays in NAFLD treatment. As such, both exercise/PA and resistance training are useful in reducing risk for MetSyn and NAFLD by optimizing muscle and liver function and health.