Exercise and the heart – when to shift to “lower gear”?

The marathon, the pinnacle of classical sports, besides being the longest discipline of the queen of sports, is a symbol of rememberance of a great personality from the time of ancient Greece – the messenger Pheidippides. After the victory of the Athenians over the superior Persian army in the battle on the plain of Marathon, he hastened to Athens to announce the important news. On that path, he ran about 40 kilometers and fell dead from the exertion as soon as he had completed his task. In his honor, marathon races are celebrated all over the world, and the Zagreb Marathon has also been held since 1992.

This discipline is just one example of a sport in which sudden and fatal consequences for the life of the athletes frequently occur despite their preparation. The reason for this is often overexertion. Therefore, it is important to ask how much is too much and when it is necessary to shift to a “lower gear” so that our heart does not give out.

Exercise, exercise, but…

It is known how much the importance of physical activity is emphasized today, and exercise has become a kind of medicine – a medicine that, if used correctly, can insure a significant positive effect on health. If we practice exercise regularly, it will help improve overall health, and above all reduce the risks of developing a number of illnesses. It reduces the risk of diseases that are the leading cause of death in the world: diseases of the heart and blood vessels. Also, physical activity improves and regulates digestion, maintains the body’s motor functions, improves bone mineralization and has a beneficial effect on mental health. So, there is no such pill that will have a positive effect on such a large number of organs and organ systems. However, it is important, as with any other medicine, not to forget about possible side effects and contraindications.

Can we measure how much exercise we need?

One international study defined how the greatest benefits for the health of the cardiovascular system were experienced by individuals who had more than 42 METs of physical activity per week. MET (metabolic equivalent of task) is a measure based on which energy consumption in metabolic reactions is monitored. It is defined by the metabolic rate at rest, which manifests itself with an oxygen consumption of 3.5 mL per kilogram of human body weight.

In addition to this unit of measurement being quite demanding to calculate and to the average person undoubtedly confusing, it is also almost impossible to develop a unit of measurement that will define ideal doses of physical activity. Namely, the amount of physical activity that this study defines as optimal is actually far below the amount that many athletes routinely perform. Many runners, for example, have over a 100 METs of physical activity per week, which is far more than what the study defined as ideal.

An Australian study showed that about 40% of their population engages in exercise three or more times a week and thus certainly exceeds the ideal activity threshold given by the international study. Additionally, several Australian triathletes responded to the survey and were found to have a weekly exercise regimen of more than 20 hours or 300 METs. So, the data varies significantly, and many still play sports without major difficulties and consequences. Everything is individual!

What is athlete’s heart?

While the question of the correct amount of exercise is still being answered, it should be kept in mind that it affects a number of changes in the human body, the most significant of which are changes in circulation, metabolism, but also morphology, above all, of the heart. How does it affect morphology? Namely, constant and intense physical exertion leads to changes in the structure of the heart, i.e. the occurrence of hypertrophy (enlargement) of the heart muscle, bradycardia (decrease in heart rate), increased capillarization of the heart and the like.

All these changes in the normal structure and function of the heart are collectively known as athletic heart syndrome, which is most pronounced in those who do endurance sports. It should be kept in mind that this is not a pathological condition, but a normal phenomenon by which the organism adapts to newly created conditions of greater strain. In addition, numerous studies support the fact that athlete’s heart in itself is not the cause of pathological occurrences in the cardiovascular system, and above all not sudden cardiac death.

When the heart says “that’s enough”…

The occurrence of sudden cardiac death is something that all professional players fear the most. Numerous studies have shown that the main cause of sudden cardiac death (cardiomyopathy, coronary artery anomalies, etc.) are congenital, or present since birth, heart diseases. This mainly pertains to athletes under the age of 35, while atherosclerosis of the coronary arteries is the main cause of death in those who are older. In these individuals, atheroma rupture and subsequent thrombus formation may occur during physical activity. Looking at all cases of sudden cardiac death, it is exactly atherosclerosis of the coronary arteries that is the cause of 80% of the cases of this phenomenon. However, the occurrence of sudden cardiac death is extremely rare, but it should not be ignored as well as all other acute phenomena that can happen to players while they are on the field, such as a heart attack.

Prevention above all!

In order to prevent all aforementioned problems, it is important to take the first step in prevention, namely systematic examinations and control checkups. Such examinations must be performed throughout the lifetime because some diseases can appear even in old age. Unfortunately, the fact is that examinations are often (not) performed in an appropriate manner, which leads to consequences that can be life-threatening. In addition to the examination itself, a complete blood count analysis is also important, and instruments such as an EKG are used to examine the heart. Today’s medicine, as can be seen, offers numerous possibilities that lead to fast and safe diagnostics. It is also necessary to educate athletes on its importance and how much examinations can help them.

Don’t let the diagnosis discourage you

Playing sports, especially if it is intense, leads to changes in the function and structure of both the heart and many other organs and organ systems. As our skeletal muscles increase due to strength exercises, so does our heart, and athletic heart syndrome can be considered a normal phenomenon – a phenomenon that is not the cause of heart disease and sudden cardiac death. In order to prevent such undesirable outcomes, it is necessary to invest effort and time in prevention. The introduction of thorough systematic examinations is not only important for the safe practice of sport, but also saves lives.

If heart diseases such as cardiomyopathy or arrhythmias are diagnosed, the individual can no longer engage in competitive sports; but recreational and adapted training is more than welcome. Therefore, the diagnosis is not the key that closes the door forever, but the key that opens it, and behind it lies a healthier, safer and guaranteed better life.