As explained in previous articles, vascular health depends on the endothelial lining of blood vessels. Physical activity may help prevent endothelial disease by increasing blood flow and shear stress, which stimulates production of beneficial nitric oxide (NO). In some cases, regular exercise may even be able to restore endothelial health in persons with heart disease, diabetes, or other chronic conditions.

Cardiovascular Disease

After 12 weeks of regular aerobic exercise, people with or without high blood pressure had increased blood vessel release of nitric oxide (NO), which signals the endothelium to relax blood vessels and increase blood flow.¹

Exercise increases NO levels in the blood vessel wall by enhancing activity of an enzyme known as endothelial nitric oxide synthase (eNOS), which limits heart dysfunction and abnormal enlargement in patients with heart disease.^2,3 Exercise training is therefore recommended to prevent and treat cardiovascular conditions.²

Aerobic exercise training at moderate intensity 3 days a week for 6 months improved blood flow, endothelial function and vascular health in pre- or post-menopausal African American women, who are known to be at increased risk for cardiovascular disease.⁴

Among patients with coronary artery disease, 6 months of aerobic exercise training performed at high frequency was more effective than low frequency training at increasing endothelial function.⁵

What’s even more exciting is that the improvements in endothelial function brought about by exercise and antioxidant intake are clinically meaningful. In patients with peripheral artery disease, these interventions may improve pain-free walking distance, allowing them to carry out more daily activities.⁶

High blood levels of homocysteine increase risk for coronary artery disease, but exercise may mitigate this risk by reducing oxidative injury and restoring endothelial function via its effects on NADPH oxidase.⁷

Another cardiovascular risk factor is high lipid levels. When boys exercised before high-fat meals, they had less endothelial dysfunction after eating than those who were inactive.⁸

Serious complications of cardiovascular disease which may respond to endothelial benefits of exercise include abdominal aortic aneurysm ⁹, heart transplantation¹⁰, cognitive impairment caused by small strokes¹¹, and pre-eclampsia of pregnancy.¹²

Other Chronic Diseases

Exercise, alone or in combination with better diet or other interventions, appears to improve damaged endothelial function and physical fitness in type 2^13,14 and type 1 diabetes¹⁵, resulting in better control of blood sugar. High-intensity interval training appears to improve endothelial health as well as other metabolic and cardiovascular risk factors, particularly obesity, in patients with type 2 diabetes.^16,17

When obese people exercise, their muscles release a protein known as irisin, which increases the diminished levels of circulating endothelial progenitor cells involved in restoring damaged endothelium ¹⁸. Aerobic exercise in obese or overweight adults not only improves endothelial function but also increases levels of VEGFA, which controls growth of new blood vessels, in subcutaneous fat.¹⁹

Even a single session of aerobic exercise may prevent reversible endothelial dysfunction associated with drinking sugar-sweetened beverages, which is a major culprit in the obesity epidemic.²⁰ To help overweight children improve endothelial function, a video game involving dancing is highly effective.²¹

Cancer patients who exercise have increased numbers and improved function of natural killer (NK) cells, which appears to result from better endothelial function, shear stress, and NO signaling. NK cells are a type of immune cell linked to better cancer outcomes, including longer periods of being cancer-free.²²

Inflammatory and autoimmune conditions in which exercise may help restore damaged endothelial function, thereby reducing symptoms, include rheumatoid arthritis.²³

What If We Overdo It?

Like all good things, exercise can be overdone, potentially damaging the endothelium rather than healing it. This may occur in professional ballet dancers²⁴ or endurance athletes. Highly trained cyclists may develop an arterial disease known as endofibrosis, with progressive thickening of the endothelial wall in a major leg artery. However, this rarely occurs before cycling a total of approximately 75,000 to 93,000 miles²⁵, so most of us don’t have to worry.

Intense physical training could potentially damage the endothelium by using up antioxidants and increasing free radical production, thereby decreasing blood vessel relaxation controlled by endothelium.²⁶

So the take-home lesson for most of us, whether in good health or dealing with chronic disease, is not to be a weekend warrior. Instead, we should engage in a regular program of moderate or even vigorous exercise, provided we allow time for our bodies to recover and adapt to the effects of shear stress. ²⁷ Ask your doctor about which exercise prescription is right for you, and move on to vascular health!

Laurie Barclay, MD

Laurie Barclay, MD, is a neurologist who has published more than 60 peer-reviewed journal articles concerning her research on Alzheimer’s disease and other dementias. She is editor and author of several chapters in “Clinical Geriatric Neurology,” a medical textbook which has been translated into Italian and has also written many other medical book chapters both for physicians and for the lay public. She has been an invited speaker on her own research and on other topics at medical and scientific meetings and lectures worldwide.

Dr. Barclay received her BA from Princeton University in 1974 and her medical degree from Cornell in 1978. Her training includes a medical internship and neurology residency at the New York Hospital-Cornell, and a fellowship in neurobiology at the Burke Rehabilitation Center-Cornell, where she also served as chief of the spinal cord trauma unit and clinical director of dementia research. After being an assistant professor of neurology at the New York Hospital-Cornell from 1983 to 1987 and at the University of South Florida from 1987 to 1992, she went into private practice and medico-legal consulting.

Dr. Barclay is board-certified in neurology by the American Board of Psychiatry and Neurology, in forensic medicine by the American Board of Forensic Medicine, and in traumatic stress by the American Academy of Experts in Traumatic Stress. In addition to being an associate in the American Academy of Neurology and in the World Federation of Neurology Research Group on Dementia, she is a member of the American Medical Writers Association, the American Medical Association, and the American Association for the Advancement of Science. Her many awards include 1993 Woman of the Year and listings in “Who’s Who in the World” and in other “Who’s Who” directories.

While freelance writing for WebMD, Dr. Barclay is also Senior Medical Editor for the “Medical Disability Advisor,” and is writing a memoir about her life as an amateur ballroom dance champion with her husband and partner, Richard Collett.