Regular exercise also increases a person’s immunity as more red and white blood cells are produced. White blood cells are the human natural defence to pathogens and infection. The increase in the number of white blood cells will mean there are more white bloods to engulf bacteria (phagocytes) and to produce antibodies (lymphocytes). This will lead to a more rapid destruction of pathogens infecting a host. The cardiac output (the cardiac output is the volume of blood pumped from the left ventricle each minute) of a person also increases with regular physical exercise. This is a benefit to a fit person who is unwell, as white blood cells will reach the pathogens causing the illness at a faster rate than someone who is unfit will. The system is seen as a bodily reserve.4
One of the greatest physical benefits of exercise is the reduced risk of coronary heart disease. Coronary heart disease is the most common cause of death in the western world. The risk is reduced as the regular exercise helps to increase the strength of the cardiac muscle. This means that the contractions of the heart are more powerful, so the stress on a weak heart contracting more regularly is lowered.
One great effect of regular exercise is that it reduces the physical stress factors that the heart incurs during a normal day by making the cardiovascular system more efficient.
The resting heart rate of a person decreases; therefore the heart will need to contract less, reducing stress placed on the cardiac muscle. The heart increases the stroke volume, which lowers the resting heart rate. The lower heart rate also means that blood pressure is lowered. High blood pressure is also another major health problem with people in the age range 50-704, 9. However, stress can also cause high blood pressure. Stress can also be relieved by exercise.
Exercise does not only take effect on the cardiovascular system, positive effects are also seen on the skeletal system of a human being.
Exercise increases the bone mineral density. This will strengthen bones and reduce the risk of developing osteoporosis. Osteoporosis is a disease in which bones become fragile and more likely to break. If not prevented or if left untreated, osteoporosis can progress painlessly until a bone breaks.
An active person has less risk of developing some forms of cancer, for example breast cancer is less common in physically active women than it is in inactive women. The risk is reduced due to exercise reducing the level of oestrogen produced by the ovaries. High oestrogen levels have been linked to being a cause of breast cancer.
Exercise does also produce physical risks. Exercise places very different demands on a person’s bodily system1.
As stated above, exercise helps to maintain body mass by burning calories. An average man who does regular exercise burns between 2000 and 3000 calories a week. These men have significantly lower numbers of death at an early age than men who don’t exercise do. But men, who do extensive amounts of exercise in a week and burn more than the 3000 calories a week, the protective effect of a healthy body is lost and death rates start to increase. This is very common in elite athletes who often suffer from immune suppressions. The large demand put on the athletes by there event means they often neglect what is a safe level for them to be at, all to be the best at their event. This is also a mental factor that effects why people exercise. The endorphins (endorphins are natural painkillers produced by the body during activities) released during exercise lead to happiness7.
Also excessive exercise produces particles called ‘free radicals’. These molecules cause great harm to a healthy body, they do this by attacking the healthy cells of the body systems. During strenuous exercise, some parts of the body produce more than 200 times more free radicals than at rest. The deformation of the healthy cells can lead to diseases from cataracts to cancer (although exercise can reduce the chance of cancer in some parts of the body)7.
Injuries often occur from exercise. These injuries can be either acute or chronic. A fall or collision causes acute injuries. This may happen during physical exercise. These lead to fractures in the hard tissue e.g. a broken leg, also soft tissue injuries such as bruising. These injuries can cause a lot of pain and can change a person’s life if they are serious enough (a skiing accident may end in a wheelchair.)
Chronic injuries are caused by a continuous stress on part of the body over a long period of time, due to the overuse of certain muscles. These are very painful and can be harder to recover from if they are neglected. Also chronic injuries can stay with someone into later life. The most common chronic injuries are knee troubles (cartilage problems and ligament trouble), also problems with the back. The back problems caused by extra stress on the joints between each vertebra.
Anaerobic exercise (extremely strenuous exercise completed without oxygen) produces a waste product called lactic acid. When muscles contract at high speed in the absence of oxygen, the waste product lactic acid is produced (Lactic acid is a strong acid. This means that when it is produced it rapidly dissociates into lactate and hydrogen ions, causing in pH). Lactic acid pools in skeletal muscles and causes fatigue.2 Fatigue will mean the muscles will not be able to contract as powerfully and in some serious cases not at all. Fatigue causes a discomfort to the person and often causes aching.
The production of carbon dioxide increases during exercise. It combines in the blood stream with water to produce a weak acid, carbonic acid. This weak acid, in higher concentrations, can cause hyperventilation. Hyperventilation is when the rate of ventilation is higher than the rate of carbon dioxide production. This increased rate of breathing is to compensate for the low pH of the blood.
In conclusion, the physical effects of exercise are more beneficial to a person than problem causing.
Exercise also has mental benefits to person.
Regular exercise can help to reduce a person level of anxiety. One of the most looked at benefits to mental health caused by doing physical activities is stress management. People who do physical activities and exercise can manage their stress levels a lot better than people who do not exercise can. Therefore people who have regular exercise end up being less ‘stressed’. Stress is reduced as the body produces endorphins and these stimulate happiness.
Exercise is also known to relieve depression. It stimulates the release of endorphins. These endorphins help to trigger the chemical, which controls mood in the brain.4; A person’s self esteem can also be greatly lifted by competing in physical activities.
A great risk is that people become obsessed with exercise and become fanatics. They become obsessed with what they feel is peak physical condition and end up going to any length to get to this level. This can cause physical problems such as the body is working so hard that the positive factors gained from exercise are cancelled out and these then become negative factors.
I conclude that in general, exercise has physical and mental benefits and these benefits are greater than the risks that are associated with a lack of exercise or too much exercise. This is only true as long as the exercise is completed within moderation and that it is not too strenuous. Also that the person has a recovery period.
