What are the physical benefits of exercise?
1. Introduction
Nowadays, the fashion for being a fit is strongly implanted in the heads of millions of people around the world. Glorified are muscular, slim silhouettes with low levels of body fat. Each of us can think or think that we would like to have a similar silhouette to those that bombard us at every step of the way with instagram, Facebook or television. So far, this approach is very wishful thinking, because with the implementation of it in life is much worse. This is perfectly illustrated by the study published in Nature in 2017, where Althoff et al. tried to create a map of the frequency of physical activity in the world. The survey involved 700,000 people from 111 countries. Records from the participants’ smartphones were used for the analysis. In total, the data represented 68 million days of physical activity. Physical activity was measured by the number of steps taken by a participant per day. Data analysis showed that the average number of steps covered by the respondents was 4961 in 14 hours per day. The highest number of steps (almost 6,000 per day) is observed in Japan, Belarus, Ukraine, Russia, Spain and China. The lowest number (less than 4 thousand a day) is in Saudi Arabia, Libya and Indonesia. The average number of steps of the United States, which in other scientific studies are presented as not physically active, has reached the result of 4774 steps per day. Cities like New York and San Francisco showed the highest average number of steps from all cities in the United States. The lowest was Houston and Memphis.
According to the World Health Organization, physical activity is any form of physical activity produced by skeletal muscles, which requires our body to expend energy. The most common physical activity in the world is walking, running and cycling. However, we should not limit ourselves to these forms and introduce other more complex forms of activity, such as team sports, tennis, squash and swimming. Recommendations suggest that an adult not connected with sport, who wants to take care of his or her health, should spend 150 minutes a week on physical activity, and in case of weight loss or improvement of condition 300 minutes. Insufficient physical activity according to WHO is one of the main risk factors for the occurrence of non-communicable diseases such as diabetes, hypertension, depression or coronary heart disease.
2. Regular exercise has many benefits for our body.
Physical activity should be practiced most of the time, until we are able to move on our own. Physical exercise in old age slows down the aging process. Older people should focus primarily on strength training, which slows down the rate of muscle strength loss and delays the impairment of mobility and normal functioning.
The more regular and systematic our physical activity is, the more the impact of exercise will be better felt and our body will increase its sporting performance.
2.1 Weight control
Physical activity is one of the main criteria to help regulate the energy balance. This helps to control the composition and weight of the body.
2.2 Influence on the circulatory system
Physical activity of endurance character, e.g. long distance running, has the greatest influence on the circulatory system. As a result of these exercises, our body undergoes adaptations, which contribute to the reduction of heart rate contraction with a simultaneous increase in the volume of ejection. This is the natural behavior of our body, which aims to maximize the efficiency of energy consumption during physical activity. Our heart beats less often, needs less oxygen to work, but the volume of blood that it pumps in 1 minute does not change. Regular physical activity also reduces blood pressure at rest. The blood flow through the working muscles during very intensive efforts decreases, while the blood supply to the internal organs and skin increases.
2.3 Effects on the respiratory system
Physical exercise of endurance character has a positive influence on the functioning of the respiratory system. The most noticeable effect is the improvement of the work of the diaphragm and intercostal muscles, which participate in breathing. The indicator, which is called the ventilation threshold, is also improved. It determines the moment when our body can effectively deliver oxygen during an extremely intense exercise. The mobility of the chest during breathing is also improved and lung capacity is increased.
2.4 Effects on the hormonal system
Physical effort changes the hormonal balance of our body. A single session of physical activity affects most hormones. It is also important to determine the nature, duration, intensity of exercise and our level of training.
For example, a change in the secretion of sample hormones after a single session of physical activity.
• Insulin
Almost every effort (apart from low-intensity efforts of short duration, e.g. a 15-minute walk) reduces insulin levels in the blood. The longer the activity, the more insulin is lost. In long-term, moderate intensity workouts, carbohydrate intake during the start should be kept in mind as hypoglycaemia is not allowed.
Our tissues are more sensitive to insulin at the end of their activity.
• Testosterone
Short-term, very intensive physical activity increases testosterone secretion at the end of exercise, but this increase is short term. The higher the training load, intensity and number of muscles involved, the higher the increase in testosterone will be.
Mostly at the opposite pole for this hormone is endurance training. During prolonged efforts, a decrease in testosterone levels in the blood is most often observed.
• Cortisol
The increase in cortisol secretion is observed in efforts with a load of at least 50-60% VO2 max. This concentration increases with increasing intensity of the effort. Other factors such as hypoglycaemia, body temperature rise and emotions that increase cortisol secretion may also occur during prolonged, moderate intensity training.
After a very intensive exercise, the concentration of cortisol increases only after several minutes after the end.
2.5 Effects on bone tissue
Between the ages of 35-50, both sexes (women over 30 years of age) will experience slow bone mass loss. There is about 10% loss of spongy tissue and 2-4% of compacted bone tissue. Physical activity (even at the level of recreation) is a basic preventive measure against osteoporosis in old age. Osteoporosis is mainly a problem for women due to lower peak bone mass compared to men. It was found that regular physical activity in women between 25 and 35 years of age significantly reduces the risk of postmenopausal osteoporosis.
