The influence of physical activity of varying intensity (insufficient, excessive, optimal) on the human body

Since childhood, we have all been taught that physical education and sports are best friends strong and healthy body. Sometimes it was equated with physical education and physical labor. It, according to many, develops muscles and thereby makes a person healthy and hardened. However, it is not. Physical work is more likely to lead to disproportionate development separate groups muscles, and its health only worsens. And some researchers question the benefits of playing sports.

He who works does not exercise

Many of those who perform heavy physical work believe that they do not have to play sports - the workload at work allows them to keep themselves in good shape. As Croatian researchers found last year, this is not the case.

The fact is that in most cases, physical activity at work, unlike exercises, is not selected in terms of volume, intensity and duration. That is, those who believe that they only exercise at work by standing, walking, lifting weights or working with their hands. As a result, their arm muscles develop well, but the rest of the muscles may even be in worse condition than those who work in an office and do not play sports.

The study by Croatian scientists involved men aged from 20 to 60 years old, divided into two groups, differing in the intensity of workload. To test the strength and elasticity of the muscles, the experiment participants were offered several exercises, and only in one of them - squeezing the fingers - those who did hard work showed greater muscle strength.

In other exercises, especially those showing the elasticity of muscles and ligaments, office workers those who did not engage in sports were far ahead. These results indicate that, despite physical exercise at work, it is necessary to perform a set of exercises that makes the load on all muscles even.

Physical work is certainly easier for young people. Moreover, at the age of up to 35 years it can be useful. But even sports may be contraindicated for people older than middle age.

Relaxing on the couch is the best exercise

In some cases, physical exercise is certainly beneficial. In addition to the fact that they help fight overweight, physical activity reduces the risk of atherosclerosis and other cardiovascular diseases, as well as impotence and peptic ulcers.

However, in some cases, the path to longevity may not lie through gyms, exhausting runs and swimming in cold water. For many people, the best exercise machine that ensures their health is long years, can become your favorite sofa, best exercise - nap, and the best motivation for “studies” is simple healthy laziness.

German professor Peter Axt came to such absurd conclusions at first glance. In his book The Joy of Laziness, which came out a few years ago, he encourages readers to simply waste their free time enjoying doing nothing. In his opinion, people who force themselves to the gym in order to indulge in an activity that does not bring any joy are harming themselves. But laziness, in addition, serves as a good protection against stress.

Professor Akst does not deny people the right to exercise. In his opinion, it supports well easy shape a walk, but nothing more. This applies primarily to older people, who must carefully monitor their energy expenditure. Studies have shown that people over 50 who run spend energy on it that they absolutely need for other purposes. They, according to Axt, may experience memory loss and accelerated aging.

Other experts agree to some extent with the professor’s conclusions. In their opinion, physical activity should be selected individually and should be part of a lifestyle. If a person is forced to commit violence against himself every time just to get to the gym, he should look for other exercises that will bring joy and satisfaction. Twenty minutes of physical exercise three times a week is already a good level of exercise for a person who does not crave athletic achievements.

We must not forget that health is determined by experts World Organization health (WHO) as a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity. Is there really such an urgent need for slim figure, an athletic fit body, powerful pumped up muscles, if they belong to a twitchy nervous subject who is constantly in conflict with relatives, friends and neighbors?

What hurts athletes?

When we are not talking about morning exercises, but about serious sporting achievements, the body, like any means of production, wears out. It's about not only about injuries - a separate department has even been created for them in the CITO - but also about chronic diseases.

Those who practice ballet professionally - and this can also be considered a sport - are characterized by growths on the bones of the foot. Weightlifters suffer from spinal diseases. Football players, in addition to ligamentous injuries, suffer from joint diseases. The list goes on.

The purpose of this note was not to force readers to give up playing sports: sedentary lifestyle life is even more harmful. However, in physical activity, as in many other things, moderation is important.

Sports activities are certainly useful; every person should have physical activity; they help maintain muscle tone, train endurance and physical strength. It is rare to hear about the dangers of sports, since sports are considered a very useful activity, but there is also a flip side to the coin.

Morning exercises are simply necessary in order to properly disperse the blood throughout the body, improve blood circulation, and prepare the body for full-fledged work for the whole working day. However, when it comes to physical activity, it seems to some that the more the body experiences it, the healthier it becomes, and there are people who, without sparing themselves at all, try so hard to exercise that by the end of the day they simply collapse from fatigue. This is, of course, bad; all the benefits that physical exercise can bring to the body are literally reversed. reverse side. The only exceptions are professional athletes, whose training process is compiled according to a clear schedule, and sometimes, in order to achieve certain heights, they do not spare themselves and their body, however, with properly scheduled training, sport brings undeniable benefits to human health, but some Negative consequences Sometimes it still leaves behind. But we are talking here specifically about the dangers of physical activity, when people sometimes do not correctly calculate their capabilities and can greatly harm themselves.

hard work

There are people who do hard physical work, some believe that workers in such professions as a loader are incredibly strong and full of health, however, often too hard work can only take away from it. Most main harm from physical exertion at work, this is that they are completely unbalanced, for example, a person unloads a car with heavy bags, he bends down, takes the bag, and straightens up with the weight of this bag, and does this work a dozen or even a hundred times without a break , while its other muscles practically do not work, or work to a much lesser extent, in in this case there is a disproportionate load on the back and spine, only the lower back muscles work and naturally in such cases the muscles in this place are far from strengthened, but on the contrary, they only wear out. With such long and unbalanced loads, they can develop various kinds injuries, and subsequently diseases of the back and spine, this is just one example when there is an uneven load on the muscles. If we compare hard work with sports training, then during training various exercises are done to different groups muscles, the severity and intensity of the exercises is taken exactly as the athlete is ready to overcome. In addition, rest is very important for muscles, which they often do not receive, so physical work is often more harmful than beneficial.

harm to sports

Training in the gym may also not always be safe, especially for beginners, often, having come, for example, to Gym, unprepared people do not choose the right weights or begin to rush from one exercise to another, and, as a rule, without warming up. Warm-up is very important when playing sports; it warms up the muscles, making them more flexible, improving their readiness for stress and development. In many cases, it is precisely because of the lack of knowledge of what to do and the lack of warm-up that sports injuries so often occur in beginners; the most common injuries are on sports training These are muscle and ligament sprains. It happens that a person incorrectly assesses his real capabilities, and then the next day he cannot get out of bed due to severe pain in the muscles, this is all due to the accumulation of lactic acid in the muscles, especially if the person has not been involved in sports for a long time or has never done sports before.

Of course and professional occupation sports, and in particular the physical activity that an athlete is constantly forced to endure is not in vain, harm from physical activity in sports is due to the rapid wear and tear of the entire body, since resources are exhaustible for everyone, even the most enduring, and athletes spend them at multiple speeds. Professional injuries in athletes are most often diseases of the joints, since the main blow falls on them. Older athletes often suffer from headaches; in addition, old injuries often make themselves felt.

active exercises

Harm from vigorous physical activity, such as running or cycling, can be dangerous for people in later life, especially if they are just starting to run. Usually after 40 years, many people start their own physical state to unsatisfactory, and some decide to put themselves in order, lose weight and get in shape, but do not think that they have never been involved in sports before and their body is not adapted to such active actions, and after the first lap at the stadium they may feel pain in the heart, dizziness, shortness of breath, darkening in the eyes, etc., these are signs oxygen starvation, the body does not have enough oxygen to nourish the muscles, it is especially important if after the age of 35-40 you are going to start playing sports, be sure to check with your doctor for the presence of hidden diseases, which may still be early stages, and you yourself may not know about them, since nothing bothered you, and if you have even minor problems with the heart, kidneys, lungs, or low blood pressure, cholesterol, etc., you should be more wary about playing sports and not rush right off the bat. Although sport is most often beneficial for the body, it will not cure such diseases, but may, on the contrary, aggravate the situation, so think about harm from physical activity, if you are over 40 years old, the harm of sports may be much greater than its benefits.

The harm of physical activity is dangerous for people with congenital diseases spine, osteoporosis, increased blood pressure, diabetes mellitus, diseases of cardio-vascular system and other bone diseases and internal organs, If congenital pathologies you or your child have, then be sure to consult with your doctor about the opportunity to play sports in order to subsequently avoid the harm of physical activity or sports injuries and maintain your health.

The ideal type and amount of loads from a scientific point of view

Few people have thought about pushing their limits of endurance the way Benoit Lecomte did. He was the first man to sail across the Atlantic Ocean. He now plans to swim across the Pacific Ocean from Tokyo to San Francisco - a wet and lonely 8,800 km journey that will take about 5-6 months.

According to NPR, "Lecomte, who lives in Austin, Texas, is returning to the ocean to raise awareness about environmental issues... During his swim, he plans to collect material from the Pacific Ocean, including microbes and trash."

People can visit his Facebook page, The Longest Swim. This is the perfect example of extreme exercise, and cardiologist Dr. Benjamin Levine, director of the Institute of Exercise and Health environment, will monitor Lecomte's heart function and health during this event. To do this, it will use the same technology that NASA uses to track the health of astronauts on the ISS.

Most likely, Lecomte will harm his heart, because contrary to popular belief, “a lot” does not equal “better” in the case of physical exercise. There is a limit beyond which the harm caused exceeds the benefit.

Exercise is great medicine when taken in the right dosage

Modern fitness research contains many claims that physical activity is one of the most “preventative drugs” against various diseases from mental disorders to heart disease, diabetes and cancer. For example, a meta-analysis of 305 randomized controlled trials comparing the effectiveness of exercise and... drug treatment for cases with fatal found that there was “no statistically supported difference” between the benefits of exercise and medications for prediabetes and heart disease.

One of the key health benefits of exercise is that it normalizes glucose, insulin and leptin levels by optimizing the functioning of their receptors. This is an important factor for general health improvement body and prevention chronic diseases. Exercise also promotes health and longevity by forcing your mitochondria (the small intracellular "energy stations" that produce ATP) to work harder and replenish increased energy costs.

Side effect - slowdown biological aging. However, as with other drugs, it is a matter of dosage. Too little physical activity will not bring benefits, but will make things worse, since chronic inactivity is an independent risk factor for chronic diseases and early death.

On the other hand, excessive exercise is harmful. As Dr. Levine noted, while endurance athletes live 20% longer than non-athletes, that is, those who do not run, it is also clear that if you overdo it, you are at high risk of health problems.

One of the risks of excessive high-intensity cardio training is that you can cause your heart to become enlarged. This sometimes leads to diatonic dysfunction, which can subsequently lead to heart failure. This disease is epidemic in the United States.

The ideal dosage of exercise for health and longevity

The study found that 40 to 50 minutes of vigorous daily exercise or more than an hour of moderate exercise (such as walking) is ideal. The benefits of training stop as you increase the load, and further efforts will not bring additional improvements.

One of the largest, longest, and most recent studies has shed light on the boundary of the “zone of life.” Those who engage in walking or other activities moderate loads for 420 minutes a week (an hour a day, seven days a week) reduces the risk premature death by 39% compared to those who do not engage in this load.

Those who exercised 3.5 hours a day had a 31% reduction in mortality risk. The same pattern is observed among those who tend to exercise 150 minutes a week (about 20 minutes a day).

Another large-scale study that focused on the intensity of training found that spending 30% of your entire workout on vigorous, high-intensity exercise could reduce your risk of premature death. While if you avoid increasing the rhythm of your training, you will not get the same result.

When it comes to intense cardio training, previous research (discussed on TED) has shown that to improve your health, you need to run between 8 and 32 kilometers per week, ideally between 16 and 24 kilometers per week. Once you reach 40 kilometers per week, you again reduce the benefit of the load to zero.

Also, if you run too fast (around 13 km/h) the benefit disappears (note that this refers to the speed of an intense marathon, not a sprint interval). Finally, if you run seven days a week, the benefits will also disappear. The ideal amount of exercise is 30 minutes of running two to five days a week.

Thus, the key to success is moderation, moderation in load, duration and frequency. Human body was not designed for long-term extreme athletic exercise, such as fighting ocean waves for 8 hours for 6 months straight.

Exercise less - move more

Some may be confused by so many exercise recommendations because I advocate high-intensity exercise, but on the other hand, I strongly emphasize that an active lifestyle is sometimes more important than regular exercise.

If you think about it, this is not a contradiction at all. The fact is that exhausting workouts for an hour or more, and then sitting still all day will not benefit you, since the latter counteracts the former.

A study showed that 6 hours of sitting still neutralizes positive consequences for health from an hour of training. So the basis good health- this is relatively constant and regular movement, avoid sitting as much as possible because even simple vertical position has a positive biological effect.

I firmly believe that 7,000-10,000 steps per day is the key to health and longevity. Now that I'm a Florida resident, I walk on the beach barefoot for about an hour every day. I used to walk for 2 hours, but based on the information provided in the article, I realized that extra time has no health benefits. The key is balance and moderation.

This is the foundation or foundation upon which you can build your training program. top level. For maximum benefit With minimal time investment, High Intensity Interval Training (HIIT) is the perfect complement. Two to three times a week and no more, as your body needs to recover between workouts.

Walking + HIIT = natural and comfortable combination

Benefits of HIIT include cardiovascular training, muscle and strength gains, synthesis human hormone, which prevents aging (HGH peptide), also called growth hormone. It effectively stimulates your muscles to release anti-inflammatory myokine, which increases sensitivity to insulin and glucose in the muscles.

It also increases the release of fat from fat cells and its burning in skeletal muscles Oh. This is why HIIT is very effective for weight loss. If you've already included more walking in your daily routine motor activity, it will be enough to simply switch the rhythm to a regular one, in particular, dilute the fast walking with a slower natural walk.

In every study, we've learned that alternating high and low intensities have the most significant impact, and nowhere does it say you have to do HIIT at a machine-paced pace. You can make this part of your daily walking routine. By speeding up while walking, you can replenish your efforts without wasting time.

How and Why Extreme Cardio Can Harm Your Heart

HIIT has another advantage - safety. While you can overdo it during HIIT. So, the Tabata protocol should only be tried by very trained people; long-term cardio contains more risk, since your body does not have the opportunity to recover.

Prolonged intense cardio triggers inflammatory mechanisms and wears out the heart. Your heart pumps about 6 liters of blood per minute when you are sitting. When running, the volume increases to 28 and 34 liters; its structure did not provide for pumping such an amount of blood for hours every day.

With this rhythm, your heart enters a stage of overflow, which stretches the walls of the heart muscle, destroying its tissue.

Impossibility full recovery also poses a problem. Many athletes live in a constant post-workout state that resembles chronic oxidative stress. This repeated and unrelenting damage to the heart increases inflammation, which leads to the formation of blood plaques, since plaques are a way of “tying up” your inflamed blood vessels.

Over time, more damage is done and the heart may become enlarged (hypertrophy) and scarred (cardiac fibrosis). MRI (magnetic resonance imaging) scans of marathon runners reveal extensive scarring around their heart. Scientists also measured increased level cardiac enzymes after extreme exercise. The results are the same as with heart attack. This means that this type of exercise is harmful to your heart.

While you may appear healthy by some measure, you are at risk of dying from cardiac arrest, which happens to more than one marathon runner every year.

Physical activity is understood as the measure of the impact of physical exercise on the human body, consisting of alternating physical work and rest.

Physical activity can cause significant changes in the body, in extreme cases incompatible with life, or it can have a very weak effect on the body. This depends, first of all, on the intensity and duration of physical activity: the more intense and longer the activity, the greater the corresponding changes they cause. When performing physical exercises, the load is determined by volume (number of repetitions, duration of exercise, footage and weight load) and intensity (speed of exercise, rest interval between repeated exercises). The effect of load on the body can be assessed by indicators of the functional state (for example, by the value of heart rate during work or the speed of its recovery after load; by the speed of motor reaction or the clarity of movement reproduction).

Depending on the degree of impact of physical activity on the human body, there are4 types of physical activity:

Insufficient (hypokinesia, physical inactivity) – leads to the rapid extinction of basic life support processes, a decrease in the functional capabilities of the body, the development of diseases and premature aging.

Minimum physical activity (once a week) does not provide significant positive changes.

Optimal physical activity (about 4–6 times a week for 30–45 minutes) helps expand the body’s reserve capabilities and the ability to use them as efficiently as possible. Under the influence of optimal physical activity, adaptation processes are improved and the body's resistance to the effects of adverse factors increases.

Excessive physical activity leads to overwork and overstrain of the main physiological systems, the development of pre-pathological and pathological conditions (even those incompatible with life).

There are three types of physical activity: static in which there is prolonged tension of individual muscle groups (for example, forced working posture), dynamic when muscle groups alternate between tension and relaxation (for example, walking, running, swimming) and "explosive", characterized by very strong and short-term muscle tension (for example, lifting weights). In addition, there are mixed types, as well as physical inactivity (lack of any type of load, with the exception of minimal muscle activity). Dynamic loads can be of low, medium and high intensity.

At low load intensity, working muscles need more oxygen, so the heart increases the number and strength of heart contractions, the hormonal system of the adrenal glands and thyroid gland is activated, the combustion of carbohydrates increases and the absorption of oxygen by the muscles increases. Activation of special systems aimed at the hypotensive effect occurs - mechanism feedback: As the heart works harder, there will be an increase in blood pressure, and the body activates mechanisms aimed at lowering blood pressure. Since the load is small, increasing blood pressure will be insignificant, in contrast to hypotensive processes, which occur mainly due to hormonal disorders. In this case, the vessels located in the muscles, during rhythmic work, will either be compressed or released from the compression, therefore, the muscles, contracting, push blood out of the vessels, and when relaxing, fill them again. This phenomenon is described in the specialized literature as a “muscular” heart, which, in turn, helps to relieve the heart (which is why slow walks are recommended even for patients with myocardial infarction and heart failure). During physical activity, the rheological properties blood, in particular, platelet aggregation decreases, the content of high-density lipoproteins increases (almost the only substances that can dissolve cholesterol that has fallen into the plaque and “wash” it out of there).

With an increase in the intensity of physical activity, blood pressure, pulse rate, the content of adrenaline and other activating hormones in the blood increase, as well as the need for energy supply increases, and the need for oxygen increases, as a necessary substrate for energy production. If before this the main source of energy was carbohydrates, then at this stage the source is fats, the “burning” of which begins 15–20 minutes after exercise. If such loads are not long-term (the duration depends on age, state of health, fitness, etc.), then the heart and the entire body receive a good training load, and the body’s adaptive capabilities develop. Each time, performing such loads, the body adapts to this regime and works in an economical and optimal mode of activity. The optimal loads are those that cause the desired changes in the body.

At a certain stage, when the intensity of the load increases, the training effect on the body does not increase; the so-called “plateau” effect of the load occurs. If the intensity of physical activity continues to increase, a moment comes when the body’s cells are unable to meet the exorbitant growing needs for energy substances and, first of all, oxygen - the “oxygen limit”, after which the load rapidly destroys the body: the muscular system, heart, blood vessels are damaged, brain, gas, protein, carbohydrate, fat, hormonal and other types of metabolism are disrupted (cardiomyopathy due to chronic physical overexertion in athletes belongs to this class of diseases).

By doing static loads muscle tension is observed without contraction or relaxation (the muscles are tense, but no external work is observed). During static exercises, the muscles are tense, and they actively consume energy with the accumulation of breakdown products (primarily lactic acid). Since no dynamic muscle contraction is observed, but blood vessels compressed by tense muscles, the heart needs to push blood through the vessels, which have been compressed for a long time by contracted muscles. Therefore, with this type of exercise, the main load falls on the heart. In addition, not only the inflow, but also the outflow of blood is disrupted - the removal of harmful products of the breakdown of energy structures worsens, the fluid stagnates in tissues and cells, disrupting natural exchange substances. There is a release of hormones that significantly increase blood pressure, increasing the load on the heart.

Static loads also have a positive effect on the body. So, physical activity of muscles in extreme conditions has a strong training effect, manifested by a rapid increase in physical strength and endurance. Some authors note that small static (isometric) loads help activate a decrease in blood pressure. Isometric exercises are contraindicated in patients with angina pectoris, heart failure, inflammatory myocardial diseases and persons who have suffered a myocardial infarction. Isometric exercises should be performed no more than 4–5 minutes, 3–5 approaches per exercise, no more than 3 times a week, and be sure to alternate them with breathing and dynamic exercises.

"Explosive" loads harmful to the heart. With this type of load, the heart needs to provide significant muscle tension and combine both static and dynamic loads (for example, lifting a barbell). Despite short duration“explosive” loads, the heart is forced to withstand severe stress. A sharp increase in voltage from “zero” to maximum causes:

– a significant increase in the heart’s need for oxygen and deterioration of coronary circulation;

– a sharp release of adrenal hormones (adrenaline, etc.), which with repeated exercise can lead to changes in the adrenal glands;

– increased blood sugar and cholesterol levels;

– increased blood pressure and excessive stress on blood vessels under certain conditions can lead to rupture of blood vessels (heart attack, stroke, etc.);

– disruption of adaptive vegetative mechanisms, which can cause disruption of the normal functioning of internal organs.

“Explosive” loads are strictly prohibited for people with coronary heart disease, arterial hypertension, high cholesterol levels in the blood, those who have suffered from inflammatory myocardial diseases, people suffering from diabetes mellitus or have increased function thyroid gland, etc.). People with heart problems are advised to be especially careful when choosing a training regimen and structure; for people with coronary heart disease, such a one-time load may be the last.

Physical exercises have a direct effect on the human body, a distant (over time) or cumulative effect, which is manifested by the total impact of their repeated implementation. Consequently, the results of the impact of physical activity on the body in people who play sports professionally will differ.

Sports are conventionally divided into mass and elite sports.

The goal of mass sports is to increase the general physical development of a person, his work and social activity, and the reasonable use of free time - provided by the opportunity to practice more than 70 sports (athletics, volleyball, basketball, football, chess, table tennis, skiing, swimming, etc. .).

High performance sport ( big sport) allows, based on the development of a person’s individual abilities in a specific sport, to achieve maximum (record) sports results, serves as a guide to a person’s capabilities, and promotes the introduction of highly effective means and methods into mass practice physical training, stimulates the development of mass sports and physical education.

The basis of sport is physical exercise:

– strength (with maximum muscle tension);

– speed-strength (muscles simultaneously exhibit relatively greater strength and high speed of contraction);

– endurance exercises (muscles develop not very great strength and speed, but the effort is maintained from several minutes to several hours).

According to the load on the energy systems and the supply of oxygen, physical exercise is divided into anaerobic(redox processes in the body are carried out due to oxygen reserves in the blood and tissues) and aerobic(oxygen necessary for muscle activity is constantly delivered to the body through the external respiration system). The ratio of various energy production systems determines the nature and degree of changes in the activity of various physiological systems that ensure the performance of various physical exercises.

Physiological changes in the cardiovascular system during optimal physical activity:

● acceleration of heart rate;

● increased systolic and mean arterial pressure;

● increase in systolic and minute blood volume;

● increasing the power of the heart due to more intensive functioning of myocardial structures and oxygen consumption from circulating blood;

● diastolic pressure during physical activity decreases along with an increase in systolic pressure, which provides optimal conditions for blood supply to working muscles.

Physiological changes in the respiratory system during optimal physical activity:

● acceleration of breathing rate;

● increase in tidal volume;

● increase in minute volume.

Physiological changes in the blood system during optimal physical activity:

● reduction in the amount of plasma;

● decrease in the number of red blood cells;

● increase in the number of leukocytes (myogenic leukocytosis);

● increase in platelet count (myogenic thrombocytosis);

● decrease in blood pH;

● levels of glucose, free fatty acids and urea change.

Physiological changes in nervous system during optimal physical activity:

● formation in the brain of a model of the final result of activity;

● formation of a program for future behavior in the brain;

● generation of nerve impulses in the brain that trigger muscle contraction and transferring them to muscles;

● management of changes in systems that provide muscle activity and are not involved in muscle work;

● perception of information about how muscle contraction occurs, the work of other organs, how the environment changes;

● analysis of information coming from the structures of the body and the environment;

● making, if necessary, corrections to the behavior program, generation and reference of new executive commands to the muscles.

Physiological changes in the excretory system during optimal physical activity:

● decrease in the amount of urine;

● changes in the composition of urine;

● increase in the amount of phosphates;

● increase in urea and creatinine;

● the appearance of protein in the urine and shaped elements blood (erythrocytes, leukocytes);

● increased excretion by the kidneys of under-oxidized metabolic products (lactic, β-hydroxybutyric and acetic acid).

Physiological changes in the digestive system when performing optimal physical activity:

● inhibition of juice secretion function of the stomach and intestines;

● strengthening the motor function of the digestive tract.

Physiological changes in immune system when performing optimal physical activity:

● increased immunobiological reactivity;

● strengthening the body's defenses.

Athletes are characterized by high performance of muscular activity and the ability to quickly recover after heavy physical exertion. Their skeletal muscle mass and volume increase, especially those that provide strength and speed-strength work, and their blood supply improves. The heart is often enlarged, which is due to working hypertrophy of the heart muscle and, in part, expansion of the cavities of the heart ( sports heart). In this case, the myoglobin content in the myocardium increases, a powerful network of capillary vessels develops, the walls of the ventricles and atria become thickened. The resting heart rate of trained athletes is generally reduced. A decrease in heart rate (40–50 beats per minute) at rest is observed in runners and skiers who specialize in long-distance running. Changes in the respiratory system of athletes are manifested, first of all, by the general development of the respiratory muscles, an increase in tidal volume, and the ventilation capacity of the lungs. The highest vital capacity (VC) indicators are observed in skiers, rowers and swimmers (up to 7000–8000 cm3).

In children and adolescents, due to the incompleteness of the processes of growth and formation of the body, performing physical exercises is associated with relatively higher energy costs than in adults. Muscular load in children is accompanied by a significant increase in external respiration and oxygen consumption compared to adults. Regular sports training reduces oxygen consumption at rest and accelerates the development of motor skills.

With insufficient physical activity, the human heart weakens, the function of the nervous and endocrine mechanisms of vascular regulation deteriorates, and blood circulation in the capillary area especially suffers. Even a moderate load is too much for the heart muscle, which is poorly supplied with oxygen. Any unfavorable situation that requires an increase in heart activity can be dangerous to health and life. Almost 3/4 of cases of myocardial infarction occur from the insecurity of an untrained heart under emotional and other functional stress.

Intense physical activity leads to early atherosclerosis and calcium deposition in blood vessels. This news came from American scientists (publication in the scientific journal Mayo Clinic Proceedings, which is published by the famous Mayo Clinic). The results of the study are shocking. Not only very intense loads turned out to be harmful, but also ordinary ones, which we are strongly recommended to do.

If you carefully study the table from the article (we adapted it for the reader), it turns out that those who intensively and regularly loaded themselves in the gym, jogging, cycling, etc., had atherosclerosis 2 times more often than those who did not lead a very active lifestyle. The latter won even against those who acted in accordance with the advice of doctors: they dedicated physical activities 150 minutes per week (in the US this is the official recommendation).

25 years of observations

Observation of volunteers lasted 25 years. Their health status was first assessed between the ages of 18 and 30. By commitment to active image everyone's lives were divided into three groups. The first included the most passive ones; they did not run, did not jump, and did not even walk at a brisk pace for 20-25 minutes a day. The latter performed the recommended level of physical activity. The third group included the most active ones, who tortured themselves with physical activity for at least 450 minutes a week, that is, they spent more than an hour a day on it. And these enthusiasts, who were involved in a serious race for health, were 80% more likely to have poorer blood vessels than those who were lazy to do the sports minimum.

The scientists were amazed: they expected the opposite results. After all, there is an established opinion that when playing sports, cholesterol is reduced, glucose in the blood and fat under the skin are burned, the heart and blood vessels are trained, and all this delays the development of atherosclerosis.

What to do?

“There have already been studies in which similar vascular changes were detected in athletes,” explains cardiologist, doctor of medical sciences, head of department and scientific secretary of Moscow State Medical University named after. Evdokimova Yuri Vasyuk. — And in principle it’s clear why this happens. Heavy loads not only train the heart muscle, but also stress the blood vessels: high blood pressure during long and intense exercise it has the same effect as arterial hypertension. Because of this, mechanisms are triggered that contribute to the development of atherosclerosis and calcium deposition in blood vessels. It seems that in this case exactly these mechanisms were at work, because people who were intensely involved in physical exercise experienced the same stress as athletes. But, of course, we need here additional research to find out all the details.

The main thing is to focus not on the kilometers of distance, but on the state of the body. This can be determined by heart rate, calculating the optimal load using Shepard's very simple formula (see infographic). With its help you will determine the maximum permissible frequency heart rate during exercise for your age. It’s good if during exercise your heart rate is 50-60% of the maximum. This usually corresponds to a feeling of light sweating. Try to stick to this load.”

Click to enlarge