Exercise too dangerous? Working out with blocked arteries could trigger a stroke

WASHINGTON — Could exercise actually be bad for your health? A new study is warning that working out could potentially cause a stroke in individuals with blocked arteries.

Researchers from India suggest that many gymgoers may be neglecting the cautionary advice provided before workout classes, which strongly encourages consultation with a doctor before engaging in vigorous physical activity. Scientists caution that certain health conditions could render the increased heart rate, associated with exercise, dangerous.

The study, conducted by a team from the Indian Institute of Technology Kharagpur, found that an increased heart rate could potentially induce a stroke in patients who have highly blocked carotid arteries. However, they also found that for healthy individuals and those with only slight artery blockages, exercise is still advantageous in maintaining healthy blood flow.

The research team clarified that the carotid arteries, located on both sides of the neck, supply blood flow to the face and the brain. These arteries can become narrower when substances such as fat, cholesterol, and other particles accumulate on the inner walls of the artery, forming a plaque.

This narrowing, known as stenosis, can be challenging to detect in its early stages when the plaque is starting to accumulate. Yet, it poses a significant risk as it can restrict blood flow to the brain. If the brain is deprived of the necessary blood supply, it lacks oxygen, leading to a stroke in the patient.

In healthy individuals, an elevated heart rate can increase and stabilize the drag force that the blood exerts on the vessel wall, thereby reducing the risk of stenosis. However, this may not be as beneficial for patients already suffering from stenosis.

To study this, the research team simulated blood flow in carotid arteries at three stages of stenosis – without blockage, with a mild blockage of 30 percent, and with a moderate blockage of 50 percent – using a specialized computer model. They then compared the effects of an exercise-induced heart rate of 140 beats per minute with resting heart rates of 67 and 100 beats per minute.

heart arteries during exercise
Contours of oscillatory shear index (OSI) on healthy, 30% stenosis, and 50% stenosis carotid arteries for the normal (67 beats per minute), moderate (100 bpm), and high exercise (140 bpm) heart rates. CREDIT: Khan et al.

As anticipated, for healthy individuals and those with mild blockages, the exercise-induced condition improved the health of the simulated carotid arteries. However, the team expressed concern regarding the results for cases with moderate blockages.

Intense exercise shows adverse effects on patients with moderate or higher stenosis levels,” says study author Somnath Roy in a media release. “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.”

Dr. Roy adds that an elevated heart rate could also increase the chances of another stenosis forming. The research team notes that many factors contribute to stenosis and stroke risk, including age, lifestyle, and genetics. They recommend checking arterial health regularly before engaging in intense workouts.

Study authors also suggest sticking to carefully-prescribed exercise regime if you have moderate to severe stenosis or a family history of suffering strokes.

The findings are published in the journal Physics of Fluids.

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South West News Service writer Stephen Beech contributed to this report.

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Comments

  1. Don’t forget to take your rutin supplement.

    “Rutin is a plant pigment and bioflavonoid; it is a potential anti- thrombosis because it has shown to inhibit both platelet accumulation and fibrin formation during thrombosis formation. The best part about rutin is it is all safe and inexpensive and can be obtained naturally in many foods”

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