Nowadays, people can use various conveniences - on the one hand an advantage and on the other a disadvantage. Convenience is related to the fact that we move less - the increasing number of cars we use to get around means that human physical activity is much less than it was a few decades ago. If we add sedentary work to the mix, the balance goes against our heart.

The human organism is programmed for physical exertion - although physical activity is not alien to our species, the need for high levels of exertion has diminished over successive stages of development. All kinds of conveniences - the development of means of transport, devices that make it easier to do household chores, the development of technology (Internet) have led to a significant decrease in physical activity. All these conveniences have led to the spread of sedentary lifestyles. For some, the only form of physical activity is work and getting to work. Most of our lives are spent sitting or lying down.
The effect of physical activity on heart function has been the subject of research by many scientists in recent years.

What effect does physical activity have on the cardiovascular system?

Physical activity:

• lowers blood pressure,
• prevents overweight and obesity,
• improves glucose tolerance,
• improves lipid profile,
• has a positive effect on endothelial function, inflammatory processes, coagulation and sex hormone levels.

Regular physical activity reduces the risk of cardiovascular disease (CVD)

Physical exertion increases the efficiency of many adaptive mechanisms due to changes induced at the level of structural and functional organisation of the body.

Systematic physical activity leads to changes in the functional regulation of the cardiovascular system, which modifies the haemodynamics of morphological changes in the heart and blood vessels, leading to changes in the properties of the heart and changes in its metabolism.

People who engage in regular physical activity, compared to those with a sedentary lifestyle, have higher fitness, physical capacity, increased exercise tolerance, and a slower resting heart rate.
Regular exercise has a very positive effect on immunity - the number of NK cells (natural killers) and their activity in inhibiting tumour growth increases. Physical exercise delays the effects of age on the heart muscle - this is due to a reduction in the expression of genes responsible for inflammatory processes and the oxidative stress response.
Physical activity also has a positive effect on mood and psychosocial functioning.

What does the research indicate?

The conclusion of the research is clear - inactivity is considered a risk factor for cardiovascular disease.

A study on the effects of a sedentary lifestyle by Nagaya (Department of Public Health, Nagoya City University Medical School, Japan) and colleagues found that sedentary work is an additional risk factor for heart disease, independent of the lack of daily non-work physical activity. The authors suggest that lower levels of physical fitness and unfavourable cholesterol levels in people who spend long hours in a sedentary position may be the cause.

It is important to remember that heavy physical work does not benefit the heart muscle. Fransson (a researcher at Karolinska Institutet in Stockholm) and colleagues conducted a study on the risk of myocardial infarction depending on the type of physical activity. The scientists found that walking or standing at work, as well as physical activity after work and doing heavier housework reduced the risk of heart attack. There was an increase in risk when lifting and carrying heavy objects. The same authors indicate that physical activity of the aerobic type (dynamic exertion) i.e. exercise and work in which one walks reduces the risk of myocardial infarction. In contrast, anaerobic type exercise (lifting) increases the risk of myocardial infarction. Studies have also found a beneficial effect on heart function of moderate physical exertion during work as opposed to sedentary work.

photo: panthermedia

Why is sedentary work so bad?

There are 4 factors that contribute to the risk of heart disease:

• bMI
• total cholesterol level
• the level of good HDL cholesterol (its inappropriate level)
• c-reactive protein - elevated levels of this protein in the blood occur during inflammation.

A study conducted by researchers at London's University College and Australia's University of Queensland on a group of 4,500 adults over the age of 34 (the study lasted four years) found that C-reactive protein levels were around 300% higher in people claiming to spend more than four hours sitting than in those claiming to spend less than two hours in the same way. The implication is that sedentary work may contribute to mild, persistent inflammation. The same study also indicated that levels of the main enzyme responsible for breaking down fats in the blood dropped by 80-90%. This is another risk factor for heart disease.

Prevention of heart disease associated with sedentary work

Nowadays, most of us have sedentary jobs. Since we can't change this, it's worth considering what we can do to avoid heart problems.
A primary preventive factor is to persuade employees to do physical activity in their free time. It is also advisable to take care of one's nutrition, eliminate stimulants, get enough sleep and carry out preventive examinations.
Introducing physical activity is therefore an easy way to compensate for the risks associated with sedentary work. It is important to remember that the minimum recommended dose of leisure-time physical activity is more than 1,000 calories per week, i.e. 30 to 45 minutes of moderate-intensity training (60 d0 70% of the maximum age-dependent heart rate) 4 to 5 times per week. Any form of activity will be good: walking, cycling, rollerblading, running, swimming - there is bound to be something for everyone.

It is worth taking care of your heart - it is one of the most important elements in the cardiovascular system. It is the most reliable and efficient pump we know, which is why it is so important to take proper care of it.