Physical activity and heart disease
Coronary artery disease is the leading cause of death in the world. Therefore, its prevention is one of the main priorities of health care. Regular physical activity has a protective effect: it reduces the risk of illness and can slow its progression. It is known that its effect in reducing the risk of death is dose-dependent: it is higher if a person is engaged.
Physical activity is central to guidelines for the prevention of cardiovascular disease. At the same time, the mechanisms of its action are not fully understood. The so-called ischemic preconditioning is currently considered to play an important role. We are talking about the occurrence during exercise of short episodes of a lack of blood in the heart muscle, followed by the normalization of blood circulation. At this time, the heart trains to resist ischemia: the body begins to rapidly produce substances that increase blood flow, as a result of which additional vessels are formed. In experiments, scientists have shown that physically active animals have smaller foci of myocardial infarction than passive ones.
Physical activity prevents instant death
Scientists from Denmark decided to find out how physical activity in the past protects against death in the acute phase of myocardial infarction: immediately and within 28 days. They analyzed data on 28 thousand people who died of myocardial infarction. Scientists have identified groups of study participants based on how active they are physically in their free time.
Within 28 days after a heart attack, almost 5 thousand people died, 62% of them died immediately. The more physically active the study participants were, the higher their chances of living longer.
People with moderate to high levels of physical activity had a 33% and 45% lower risk of instant death from myocardial infarction, respectively, than those with a sedentary lifestyle. On the twenty-eighth day, their risk of death was 36% and 28% lower, respectively.
“Almost 18% of patients with myocardial infarction died in the first 28 days, which underlines the severity of this disease. We found that physical activity in the past helps to survive immediately after a heart attack, and we see this effect extends to 28 days, ”said Dr. Kim Wadt Hansen of Bispebjerg Hospital in Copenhagen, co-author of the study.
According to the authors, their work shows that even low levels of physical activity reduce the risk of heart attack – but this statement needs additional research.
Notably, the study supports the current standards of physical activity presented in the European Guidelines for the Prevention of Cardiovascular Diseases. The document recommends 150-300 minutes of moderate or 75-150 minutes of vigorous physical activity per week.