The heart pumps blood throughout the body, which, in particular, delivers the necessary oxygen to the organs and tissues. In the event that the myocardium does not work enough, the body may experience hypoxia – a dangerous condition not only for its symptoms (shortness of breath, weakness, etc.), but posing a direct threat to human health and life. Patients with heart failure find it difficult to withstand even minimal physical activity, such as climbing stairs. At some point, they can cause collapse – a critical drop in blood pressure with possible death.
Sport allows you to avoid such dangerous conditions. With any physical activity, the oxygen demand of the muscles increases, which means that the heart begins to work harder in order to be able to pump more blood. Thus, the myocardium trains, gets used to possible increased loads and quickly returns after them to normal operation. A trained person is not afraid of even sharp loads, because his heart is able to quickly rebuild (change the rhythm) without any damage.
In addition, an increase in the intensity of the heart’s work activates metabolic processes, and this allows the myocardium, blood vessels and blood itself to recover and renew more easily. In particular, the level of “bad” cholesterol in the blood decreases, which causes atherosclerosis – the main cause of coronary heart disease with subsequent myocardial infarction.
Changes in the heart of athletes
Despite all the benefits of physical activity for CVS, sports can still be a prerequisite for serious disorders in the work of the heart. And this is due to how exactly the myocardium is modified, responding to constant loads.
Most often, athletes are diagnosed with the following conditions:
Dilation of the left atrium – an increase in the volume of the heart chamber.
Due to the fact that the myocardium during training is forced to pump large volumes of blood, the muscle begins not only to contract more intensively, but also to stretch, because in this way it can capture a larger volume of blood at a time. Dilation can be eliminated if the athlete reduces training intensity. However, if the left atrium is stretched for a long time, fibrous tissue degeneration occurs. First, the myocardium can no longer completely relax, which affects its work. Secondly, the distended parts of the heart stop pumping blood efficiently. As a result, heart failure develops, which can lead to cardiac arrest.
Hypertrophic cardiomyopathy is a change and thickening of the walls of the left (less often right) ventricle of the heart.
Although the causes of the development of the disease have not been identified until the end, nevertheless, such a pathology is often diagnosed in people who train intensively . Moreover, it is this diagnosis that is the most common cause of sudden death from cardiac arrest in young athletes during training.
Bradycardia is a decrease in the heart rate.
Normally, a healthy person has a pulse rate of 60-80 beats per minute. If the heart beats less than 60 times per minute, this, against the background of other CVD diseases, can lead to a serious deterioration in health and even disability. But if the heart constantly receives loads, which means that it begins to pump blood more efficiently in one contraction, at rest the pulse in a healthy person can be 35-40 beats per minute. Therefore, cardiologists distinguish bradycardia in athletes – a condition that is the norm and does not affect health. Moreover, such bradycardia makes the work of the heart more economical.
Fitness hypotension (low blood pressure) is an adaptive response to constant physical activity.
A decrease in blood pressure is associated with an increased load on blood vessels due to increased blood flow. The arteries of a trained person are larger in diameter, which means that at rest, with average oxygen requirements, the blood will pass through them with less intensity – the pressure will be reduced. In addition, during training in the body, systems are activated, aimed at lowering blood pressure. This mechanism can be considered compensatory – physical activity increases the need for oxygen, puts stress on the heart and thereby increases blood pressure. And the body compensates for these jumps with a response. Fitness hypotension accounts for 32.2% of all hypotension in athletes.
What is heart rate and why it matters
Why can sports affect the work of the heart so differently? Why, in some cases, it prolongs its work, and in others – leads to the development of pathologies? The main reason for this different effect is the choice of training intensity. And it is easiest to calculate it by an increase in the heart rate (HR), because it depends on this how forcefully the blood is pumped.
In order to calculate the permissible boundaries, you can use the following scheme: a number equal to the number of full years is subtracted from 220. The resulting value is the maximum heart rate (MHR). Workouts are divided into:
Warm-up, load for people with CVS diseases – 50-60% of the maximum.
Aerobic load, acceptable training for a healthy person who wants to support the heart – 60-75%.
Anaerobic load, training that can lead to myocardial pathologies – 75-90%.
Dangerous load, risk of death – 90-100%.
It should be understood that such calculations are very individual and depend on other factors. For example, for a trained athlete whose heart is accustomed to enduring heavy loads, even the maximum heart rate for a short time may not pose a danger. But for a hypertensive person, exercises in “safe” values of aerobic loads can cause a significant deterioration in their condition.
Fitness rules for a healthy heart
There are a number of factors to consider when choosing a workout intensity. If they are, it is better to give preference to lighter loads.
Being overweight in itself puts an increased strain on the heart, since it must supply more tissues with blood. In the event that the myocardium is not trained, but is under such a load, intense fitness can harm the heart.
Diseases of the cardiovascular system.
The danger is that many of them are asymptomatic in the early stages – the person is not even aware of their presence. Therefore, before signing up for sports, it is necessary to undergo a cardiological examination.
Smoking, alcohol, fatty foods, overeating.
All this gives an increased load on the heart, so it is better to give up bad habits – they are incompatible with sports.
Emotional stress, just like physical stress, raises the heart rate. Therefore, in this state, it is best to start training with relaxing exercises, and proceed to intensive ones only after the normalization of the heart rate.
If increased loads for untrained muscles end up with dizziness (delayed muscle pain syndrome), then the heart can react with various malfunctions – heart rhythm disturbances, increased blood pressure, and so on.
Therefore, for training the heart, the systematicity of the loads is more important, and not their maximum possible intensity. For a healthy person, training 3-4 times a week is suitable if an aerobic load is selected (60-75% of the MHR), and with a minimum load (less than 60% of the MHR), you can exercise daily.