The undeniable benefits of exercise on health have been extensively studied and supported by ample research and evidence. Regular physical activity plays a protective role for the cardiovascular system, improves cardiorespiratory fitness, and contributes to increased life expectancy.
Nevertheless, as individuals age and the risk to the heart becomes more pronounced, it is crucial to seek approval from a cardiologist before engaging in exercise, particularly for sedentary individuals with existing cardiovascular risk factors. Without proper medical clearance, exercise can potentially pose health hazards, especially for individuals with blocked arteries.
According to a study conducted by the Indian Institute of Technology Kharagpur, exercise-induced high heart rates can potentially trigger strokes in patients with significant blockage in their carotid arteries. However, for individuals in good health or with minor artery blockages, exercise plays a vital role in maintaining healthy blood circulation.
The carotid arteries, located on either side of the neck, are responsible for supplying blood to the facial tissues and the brain. When fats, cholesterol, and other particles accumulate on the inner walls of these arteries, plaque forms and narrow the arteries, a process known as stenosis.
Stenosis poses a serious health risk as it restricts blood supply to the brain. Initially, identifying the early stages of plaque build-up can be challenging, but once stenosis develops, reduced blood flow to the brain leads to oxygen deprivation and increases the risk of stroke.
For individuals in good health, a high heart rate helps boost and balance the drag force of blood on the vessel wall, thus minimizing the risk of stenosis. However, the same cannot be said for those already dealing with stenosis.
To explore this further, the research team developed a unique computational model to simulate blood flow within the carotid arteries at three different stages of stenosis: unblocked, mildly blocked (30%), and moderately blocked (50%). They compared the effects of exercise-induced heart rates of 140 beats per minute with resting heart rates of 67 and 100 bpm.
As anticipated, the exercise scenario enhanced the health of the simulated carotid arteries for healthy individuals and those with mild blockages. However, concerning outcomes emerged when it came to moderate blockages.
“Intense exercise shows adverse effects on patients with moderate or higher stenosis levels on patients with moderate or higher stenosis levels,” explained author Somnath Roy. “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.”
Furthermore, a higher heart rate may also increase the likelihood of developing additional instances of stenosis.
Various factors, including age, lifestyle habits, and genetic predisposition, contribute to the risks associated with stenosis and strokes. The authors of the study recommend regular arterial health assessments for individuals who engage in strenuous workouts. They also advocate for a carefully planned exercise program for individuals with moderate to severe stenosis or those who have previously experienced strokes.
The findings of the study were published in the Physics of Fluids.
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