16.5 Million Americans Risk Stroke From Too Much Exercise

While things such as daylight savings time, skipping breakfast, skyrocketing energy bills and making the bed ‘too vigorously’ have been floated as causes for heart attack and strokes (and totally nothing else), you can now add ‘exercising too hard’ to the list.

According to a new study in the Physics of Fluid, researchers concluded that an elevated heart rate can cause strokes in people with blocked carotid arteries, which occurs through a process of stenosis – where the carotid arteries located on both sides of the neck become clogged with fat an cholesterol, forming a plaque that narrows the artery.

The NY Post reports that stenosis can be difficult to catch early, and is dangerous because it limits blood flow to the brain, which can result in a stroke.

And according to the Cleveland Clinic, some 16.5 million (5%) of Americans have carotid artery stenosis.

Contributing factors to stenosis include smoking, obesity, a sedentary lifestyle, high blood pressure or cholesterol, or diabetes.

Researchers from the Indian Institute of Technology Kharagpur used a computational model to simulate blood flow in carotid arteries at three stages of stenosis: without blockage, with a mild 30% blockage and with a moderate 50% blockage.

They compared the effect of an exercise-induced heart rate at 140 beats per minute, which can be achieved by a brisk walk for some obese people, and resting heart rates of 67 and 100 bpm.

Healthy patients and those with only slightly blocked arteries appeared to have exercise be beneficial for maintaining healthy blood flow.

However, the results for those with moderate to severe blockage were concerning. –NY Post

According to author Somnathj Roy, “Intense exercise shows adverse effects on patients with moderate or higher stenosis levels,” adding “It substantially increases the shear stress at the stenosis zone, which may cause the stenosis to rupture. This ruptured plaque may then flow to the brain and its blood supply, causing ischemic stroke.”

Stroke, which is 80% preventable, is the #5 cause of death in the United States, according to the American Stroke Association.

“While stressful exercises may be beneficial for improving the cardiac performance of healthy individuals, the same may bring in extremely adverse consequences at elevated heart rates on account of extensive physical activities for patients having extensive arterial blockages, if not performed in supervision of specialized experts,” according to the report.