What Does Science Reveal About Heart Health and Exercise Frequency
Heart disease accounts for about 1 in 4 total deaths in the United States according the Centers for Disease Control. It is also the leading cause of death for both men and women. As plaque builds up, the arteries begins to narrow and blood flow decreases. Plaque build-ups can also rupture and a blood clot can form on the plaque blocking the flow of blood.
Physical inactivity is one of the key risk factors for heart disease along with high blood pressure, high cholesterol, and smoking.
If one of the main risk factors is preventable with exercise, why aren’t more people exercising?
While that is the billion dollar question, a recent study makes recommendations on the number of days a week a person should exercise to improve artery health and help prevent heart disease. The study, published by the Journal of Physiology on May 20th, 2018 by Shibata, et al investigated the impact of exercise on arterial stiffness in both large and small arteries.
The authors discussed three major findings from their research:
- 4-5 weekly sessions of exercise over a lifetime was associated with a reduction in central arterial stiffness in seniors
- Lifelong casual exercise frequency (2-3 sessions/ wk) was associated with lower carotid artery stiffness, left ventricular afterload, and central blood pressures in the seniors, but did not affect central arterial stiffness
- Peripheral arterial stiffness was unaffected by lifelong exercise training, irrespective of dose.
While 2-3 sessions a week is sufficient to improve medium size arterial health, at least 4-5 sessions of exercise lasting longer than 30 minutes a week is necessary for larger arteries to experience a decrease in stiffness. However, these benefits are not seen when individuals have only been exercising for 1 year.
This suggests that arteries require long-term exercise intervention as blood vessel structure is not reversible by exercise training alone when initiated later in life.
One theory on why the health improvements occur is that lifelong vigorous endurance exercise inhibits the remolding of the aorta to become stiff. The authors suggest that the remolding occurs based on a lifetime of exercise, explaining why 1 year of training has little to no impact.
Furthermore, total arterial compliance, blood pressure, and cardiac afterload are improved with modest lifelong exercise as well as following 1 year of training in previously sedentary seniors. This suggests that the functional components of arterial compliance are more acutely influenced by exercise.
While total aortic restructuring appears to be the result of a lifetime of health and fitness, starting exercise later in life will still have a positive impact on cardiovascular health and lower the risk of heart disease.
However, what we wish would be covered or investigated further would be the types and intensities of training and their impact on heart disease. High intensity training has been shown to have a greater impact on cardiac augmentation than steady state style training. Furthermore, it is often reported that participants will over-report exercise on participation surveys. Does a volume of 4-5 weekly sessions need to be attained? Or can artery health be improved with less sessions of higher intensity training? We hope researchers will be able to review those questions next.