Resistance Exercise Training

The metabolic effects of reduced muscle mass, engendered by normal aging or decreased physical activity, lead to a high prevalence of obesity, insulin resistance, type 2 diabetes, dyslipidemia, and hypertension.1–4 These risk factors are associated with abnormalities in cardiovascular structure and function such as arterial stiffness and impaired endothelial function. Skeletal muscle is the primary metabolic “sink” for glucose and triglyceride disposal and is an important determinant of resting metabolic rate. Accordingly, it has been hypothesized that resistance exercise training (RT) and subsequent increases in muscle mass may reduce multiple cardiovascular (CV) disease risk factors.5–8 The inclusion of RT as part of an exercise program for promoting health and preventing disease has been endorsed by the American Heart Association,9 American College of Sports Medicine,10 and the American Diabetes Association11 as an integral part of an overall health and fitness program. Cross-sectional studies have shown that muscular strength is inversely associated with all-cause mortality12 and the prevalence of metabolic syndrome,13,14 independent of cardiorespiratory fitness levels. To date, however, the evidence that RT reduces CV risk factors remains equivocal.This review will critically evaluate whether RT modifies CV risk factors and improves characteristics of CV structure and function. The topics will be limited to the effects of RT on major and independent risk factors for CV disease including diabetes mellitus, hypertension, dyslipidemia, and advancing age.4 The quantitative relation between these risk factors and CV events has been elucidated by the Framingham Heart Study4 and other studies. The topics will also include 2 predisposing risk factors—obesity and physical inactivity—that are designated as major risk factors by the American Heart Association.1,2,4 To the extent possible, this review will examine the separate and independent effects of RT in studies that did not include a concomitant …