Individuals should understand that physical fitness is an important determinant of health and this is only attainable through regular physical activity. It is also worth mentioning that a large body of research have concluded that sedentary behaviour is one of the leading causes of preventable deaths in the world.
The diseases that come from having a sedentary lifestyle demonstrate the fact that humans need to stay physically active for the simplest reason that is a requirement for survival. In his book “Move a Little, Lose a Lot,” Dr. James Levine mentioned that we have evolved to bipedalism to have an improve mobility needed to explore the world and perform tasks needed for survival. In other words, nature has programmed us to pursue and maintain an active lifestyle.
But advances brought forth by science and technology have decreased the levels of physical activities performed by men and women on a daily basis. It is important to note that in this age of modernity and automation, an active lifestyle goes beyond casual mobility. Each of us needs to pursue targeted physical activities through exercising in order to promote good health and overall wellbeing.
There are several health benefits of exercise and other similar physical activities. These include muscle growth, cardiovascular health improvement, and nervous and mental health improvement.
Exercise and importance of muscle growth
Certain physical activities, particularly anaerobic physical activities, and certain categories of training such a strength training lead to growth and maintenance of muscle mass. Beyond the aesthetic value of having defined muscles or tone physique, growing and maintaining muscle mass is an indicator of good health.
The process of ageing brings forth considerable changes in the characteristics of the body, both in the macro and in cellular levels. For instance, ageing causes shrinkage in the muscle. This condition is referred to as age-related sarcopenia.
Take note that muscle growth naturally occurs from birth and until around the time an individual reaches the age of 30. During this period, the muscle tends to grow larger and stronger. Beyond this period however, muscle mass and functions begin to degenerate,
Muscle degeneration or age-related sarcopenia occurs due to a combination of factors such as changing hormone levels, decreased capacity to synthesize protein, and physical inactivity due to lifestyle.
Physically inactive individuals tend to lose 3 to 5 percent of their muscle mass per decade after age of 30. The process of sarcopenia accelerates around the age of 65.
A decrease in muscle mass essentially means a decrease in strength and mobility. In addition, decreasing muscle mass hampers the performance of physical active and stamina—thereby creating a viscous cycle characterized by an accelerated decrease in muscle mass.
It is also important to highlight the fact that growing and maintaining muscle mass is important in weight management simply because the muscle, especially the skeletal muscle, is a high-metabolic-rate organ. Essentially, more muscle mass means more energy consumption. In turn, this means that an individual with a developed muscle mass is consuming more energy while at rest. But aside from an increased energy expenditure while resting, individuals with more muscle mass consumes more energy while performing physical activities as compared to individuals who have lesser muscle mass.
Cardiovascular health benefits of exercise
Regular physical activity or exercise prompts the circulatory system to adapt by boosting cardiovascular and respiratory performance. To be specific, the body creates more plasma—the saltwater fluid that carries glucose and other nutrients to cells and takes away cellular wastes. More plasma means that there is a greater volume of blood to pump and a thinner blood consistency resulting in more fluidity or less resistance while circulating.
In addition, the main pumping chambers of the heart called ventricles stretch in order to accommodate the greater volume of blood. Over time, the heart muscle increases in size and the entire organ strengthens.
Aerobic exercises specifically increases the size and number of branches of the coronary arteries feeding the heart. This means that there are more channels to feed the heart muscle with oxygen. In addition, this means that there would be less heart muscle damage in case of a blocked artery because there are alternative channels to feed the heart with blood and oxygen.
Capillaries also increase in number. These vessels serve the working muscles, particularly by transporting oxygen-rich blood. In addition, more capillaries improve the pumping efficiency of the left ventricle of the heart. An efficient pumping action allows the body to do more work with less effort.
Mental health benefits of exercise
The review study of Kazuhiro Imai and Hiroyuki Nakajima revealed that voluntary physical training and exercise have favourable effects on the central nervous system and brain plasticity. It is important to note that the motor cortex and spinal cord have the ability to alter structure and function in response to motor training.
In addition, the review also revealed that intensive training and exercise can also enhance motor recovery or even restore motor function in people who have been long paralyzed due to spinal cord injury or stroke.
The aforementioned nonetheless suggest that physical activities such as exercise enhance and rehabilitate nerve connections. This enhancement allows better movement coordination, faster reaction to stimuli, and better agility.
But apart from improving connectivity in the brain and nervous system, exercise and other physical activities can also improve mental health.
P. Callaghan mentioned that exercise is seldom recognised by mainstream mental health services as an effective intervention in the care and treatment of mental health problems. His review however revealed that exercise is beneficial for mental health because it reduces anxiety, depression, and negative move. It also improves self-esteem and cognitive function. Exercise has also been associated with improvements in the quality of life of those with schizophrenia.
It is worth mentioning that prolonged inactivity decreases the production of a mood-regulating hormone known as serotonin. However, exercise triggers the brain to produce serotonin as well as another mood-altering hormone called endorphin. People who exercise regularly feel a certain sense of euphoria commonly referred to as the runner’s high.
Take note that only vigorous activities result in runner’s high. Accordingly, endorphin is a natural painkiller that masks painful sensation caused by vigorous activities. This biological phenomenon has an evolutionary function that has allowed people from the past to cover long distances to haunt for food and migrate.
The study of M. Guszkowska also mentioned that exercise could also increase body temperature, improve blood circulation in the brain, and influence the hypothalamic-pituitary-adrenal or HPA axis. This physiologic influence is probably mediated by the communication of the HPA axis with several regions of the brain, including the limbic system, which controls motivation and mood; the amygdala, which generates fear in response to stress; and the hippocampus, which plays an important part in memory formation as well as in mood and motivation.
Other health benefits of exercise
Apart from the aforementioned health benefits, regular exercise or physical activities also improve the function of the immune system, particularly by reducing the level of stress hormone known as cortisol and chemicals. Note that cortisol supresses the function of the immune system while also increases inflammatory activity. Several studies have revealed that stress has varying health impacts on children as well as the mental and emotional wellbeing of adults.
Another health benefit of exercise centres on the release and regulation of important hormones in the body. Two of these hormones are epinephrine and norepinephrine, which are important in promoting physical change. Specially, when an individual exercises, his or her brain detects more muscle movement and responds by releasing these pair of hormones. In turn, these hormones increase the heartbeat, contract arteries serving different parts of the body, and stimulate the release of sugars and fats for energy.
Insulin also fluctuates while exercising. While it is true, that physical activity increases the demand for energy, it also improves the ability of the body to draw energy from stored fats.
There are also several evidences suggesting that regular vigorous to moderate activities may reduce circulating estrogen on an on-going basis in women. This would expose breast cells to less of these hormones thus resulting in the possibility of breast cancer.
Some information from the discussion above are obtained from the 2014 Longwood Seminar at the Harvard Medical School entitled, “Healthy Mind, Healthy Body: Benefits of Exercise” by Irene S. Davis, PhD, PT, FAPTA, FACSM, FASB; and Zolt Arany MD, PhD. Further details of the review study of Kazuhiro Imai and Hiroyuki Nakajima are in the article “Exercise and nervous system” published in 2009 in the journal Mechanosensitivity and Nervous System. Further details of the review of P. Callaghan are in the article “Exercise: A neglected intervention in mental health care” published in 2004 in the Journal of Psychiatric and Mental Health Nursing. Details of the study of Guszkowska are in the article “Effects of exercise on anxiety, depression, and mood” published in 2004 in the journal Psyhiatria Polka.