Resistance exercise training - Its role in the prevention of cardiovascular disease

Although randomized controlled trials among diverse populations are needed to further examine the role of RT in reducing CV risk factors, the following conclusions can be made regarding the mitigating effects of RT on the risk of cardiovascular disease: (1) RT does not appear to alter glucose tolerance or glycemic control regardless of age, unless baseline glucose tolerance is abnormal. Nonetheless, most studies show that RT improves insulin action either through reductions in acute insulin responses during an oral glucose tolerance test or increased glucose uptake during glycemic clamp procedures. Moreover, RT significantly decreases HbA1c in diabetic men and women regardless of age, and this effect is observed even in the absence of a lasting effect of RT on fasting glucose. (2) In healthy, normotensive persons, RT elicits reductions of approximately 3 mm Hg for both systolic and diastolic BP. Future studies are needed in individuals initially classified as hypertensive or prehypertensive to determine the extent to which RT lowers BP when it is elevated at baseline. Until these studies are performed, an RT program combined with aerobic exercise should be recommended for lowering BP in hypertensive adults. (3) There is some evidence that RT can increase central arterial stiffness during high-intensity and high-volume training regimens, but an explanation for this effect has not been determined. No studies have found increased BP or peripheral vascular resistance secondary to RT. (4) There is good evidence that RT reduces total body fat mass in men and women, independent of dietary caloric restriction. There is also good evidence that RT reduces visceral adipose tissue in older men and women. (5) There is little evidence that RT improves lipoproteinlipid profiles. However, total cholesterol values for most study groups have been ≤200 mg/dL at study entry. Individuals with normal lipoprotein-lipid profiles may require greater exercise stimulus and energy expenditure coupled with significant reductions in body weight in order to further improve lipid profiles. (6) Although RT by itself may have limited beneficial effects on CV disease risk factors, this mode of exercise is beneficial in the prevention and management of musculoskeletal injuries and disorders, osteoporosis, and sarcopenia. RT also reduces susceptibility to falls and prevents or delays impaired physical function in frail and elderly persons. (7) Although performing RT by itself rather than in combination with aerobic exercise appears to contribute to some aspects of CV disease reduction, the available data do not permit accurate estimation of the magnitude of the risk reduction. Thus, for the individual without existing cardiac disease whose goal is to improve their CV health and prevent disease, there is little evidence herein to challenge existing exercise guidelines that call for moderate-intensity RT to be performed in combination with aerobic exercise. © 2006 American Heart Association, Inc.