Impact of Exercise on Cardiovascular Risk Factors: Dyslipidemia

Dyslipidemia and physical inactivity are leading risk factors for the development of atherosclerotic disease, accounting together for approximately 5.8 million annual deaths worldwide. A lipid-lowering effect of exercise is commonly assumed, but in contrast to multi-modal lifestyle interventions the independent effect of exercise on lipid profiles is less well established. In this chapter, an overview of the available evidence from epidemiological studies, randomized controlled trials and meta-analyses on the effects of physical activity, exercise training and high fitness on traditional lipids is presented. A higher fitness assessed by exercise testing is moderately associated with favorable HDL-cholesterol and triglyceride, but not LDL levels. This is confirmed by findings from randomized trials and meta-analyses, but effects are not consistently observed. Regarding the type of exercise to induce favorable changes, long bouts of moderate aerobic, continuous exercise are preferred over resistance or high-intensity interval exercise. Besides absolute lipid values, exercise favorably influences atherogenic lipid subfractions. Effects on lipid levels may be increased by adding dietary interventions or offering physical activity or exercise as part of multimodal lifestyle interventions, but these effects are only sustained by long-term adherence to these interventions. Statins may cause muscular side effects in some, requiring close clinical surveillance or change of medication, but the combination of statins with exercise overall improves clinical outcomes. Thus, statins should not be withheld if indicated according to guidelines. In summary, the effect of exercise on lipid levels is modest, with small improvements in HDL and triglyceride, but not LDL levels. Nonetheless, dyslipidaemia is rarely observed as a single risk factor, and exercise remains a cornerstone of multimodal lifestyle interventions to favorably modify total cardiovascular risk.