PHYSICAL ACTIVITY: The Source of Youthful Vitality

Physical Effort

Inexorably, all things tend to randomization - disorder. And regrettably, that includes the human body. The unrelenting offensive of the forces of entropy on the human organism spontaneously hastens it deterioration. Of personal concern is how can onslaught be minimized to ensure the body’s youthful vitality. What, if anything, can be done to counterbalance this perpetual injury?

Recently, scientists have reported that a healthy lifestyle, which includes physical activity, is associated with a reduced jeopardy of dementia across all genetic risk groups.[1] In other words, physical exertion is vital for the preservation of mental well-being. Activity sustains optimal weight while increasing bone density, muscle tone and joint flexibility. Among other benefits, physical exercise also stimulates physiological health by boosting the performance of the immune system, oxygenating tissues and stimulating gut motility. It aids in the removal of toxic end-products of metabolism including urea, ammonia, uric acid and other toxic chemicals.

Mood

Studies indicate that the more vigorous the exercise the greater the derived benefit. For example, physical activities utilizing 90% of the lung capacity is more beneficial than exercises utilizing 50%. Simply put, the greater the exertion the greater the dividends. This effect is attributed to the release of natural opiates, the β-endorphins. However, dopamine and serotonin and the more recently discovered neurotransmitter, anandamide, have been found to be responsible for exercise-induced euphoria experienced by runners.[2] (Fig 1)

Overweight and Obesity

Two of the risk factors for cardiovascular diseases are physical inactivity and obesity. In the overweight and obese, immune cells stimulates synthesis of C-Reactive Protein (CRP) which plays a major role in the regulation of autoimmune diseases. (Fig 2 and 3). High circulating levels of CRP is a major risk factor for inflammatory diseases such as allergy, asthma, nephritis, arthritis, hepatitis, colitis, inflammatory bowel disease, periodontitis etc. It is also widely known that physical activity lowers the concentration of circulating CRP in the system.

Undoubtedly, sedentary lifestyles contribute to overweight and obesity. These twin afflictions are risk factors for chronic respiratory distress, degenerative joint disease, skin eruptions and infertility. Apart from cardiovascular diseases, other life-threatening conditions emerge; they include cancers, gallbladder disease, sleep apnea, type II diabetes and hypoventilation. The latter restricts breathing resulting in low levels of oxygen and high levels of carbon dioxide in the blood. Studies indicate and as much as 41% of uterine cancers and more than 10% of gallbladder, kidney, liver, and colon cancers are attributable to overweight and obesity.[3] In fact, the International Agency for Research on Cancer (IARC) has identified 13 cancers associated with overweight and obesity. These include cancers of esophagus, thyroid, breast, gallbladder, stomach, liver, pancreas, kidney, ovaries, uterus, colon and rectum.[4] (Fig 4).

About 44% of diabetes and 23% of cardiovascular disease are causally related to obesity. Globally, obesity has reached epidemic proportions. The WHO estimated more than 1.9 billion adults over 18 years are overweight; of these, 600 million are obese. More disturbing is that there are more obese than underweight people globally with higher rates among women than men. More people are likely to die from overweight-related causes than underweight. Of those who are overweight, 3-million die each year as a result. In the US, more than one-third of adults are obese. Besides, obesity/overweight is the second leading contributor of preventable deaths killing over 300,000 per year.

Despite its role in fostering robust health, less than one third of the world’s population over age-fifteen gets sufficient exercise. According to WHO statistics, infrequent physical activity is responsible for about 17% of heart disease and diabetes and 10% of breast and colon cancer. The American Diabetic Association estimated that economic costs of diagnosed diabetes in 2017 is $327 billion.[5] In contrast, frequent aerobic activity is often touted as a means of stemming the epidemic of hypertension, obesity, Type 2 diabetes and heart disease. The latter two are major causes of premature mortality. Additionally, strenuous physical activity stimulates the release testosterone and growth hormone. In men, testosterone regulate sex drive, bone mass, fat distribution, muscle mass, physical strength and red blood cell production.[6] On the other hand, growth hormone (GH), produced by the pituitary gland regulate body composition, muscle and bone growth.[7] To encourage a healthier life style, the WHO has recommended moderate physical activity for at least 150 minutes a week for people 18-64.

Cardiovascular Benefits

Vigorous aerobic activity increases the mechanical efficiency of the heart by increasing the strength and mass of the cardiac muscles. It also dilates the blood vessels. Of benefit, is an accelerated flow of oxygen, nutrients, growth factors and hormones to the tissues. Compared to sedentary individuals, physical activity consuming on average 50% of oxygen uptake has been shown to significantly reduce mortality rates in patients with cardiovascular diseases. Patients with cardiovascular diseases exhibit higher than normal levels of C-Reactive Protein (CRP). This protein is not only an indicator but a promoter of chronic inflammatory diseases. Significantly, even moderate physical activity reduces circulating CRP concentrations in the blood (Fig 5).

Immune System

Other benefits of physical exercise include stimulation of the immune system through the Natural Killer (NK) Cell network. NK Cells are a type of lymphocyte or white blood cell. These cells are an innate component of the body’s immune system and play a central role in the elimination of viral infections and some types of cancers, particularly leukemia.[8] In other words, these cellular soldiers protect by killing virus-infected cells along with the resident viruses. Similarly, NK-cells destroy tumor cells or potentially malignant cells. They are vital to health. Vigorous activity reinforces the cell-killing efficiency of these cells. Their densities are also higher in athletes and those engaging in vigorous physical activities. Indeed, the infusion of NK-cell into patients has been used experimentally to treat certain forms of cancer. Although their deployment in cancer therapy is currently experimental, their revolutionary potential as an anti-cancer agent shows promise (Fig. 6).

Excess Cortisol

Stress conditions induce high concentrations of circulating cortisol. For this reason, cortisol is called the stress hormone. Because of its detrimental systemic effects, maintenance of optimal levels of this hormone is critical to good health. Elevated concentration of cortisol produces hyperglycemia which in turn induces accumulation of abdominal fat and high cholesterol – major risk factors for heart attacks and strokes. High cortisol also suppresses the formation of T-cells, in effect paralyzing immune function.[9] In addition, raised cortisol increases inflammation and blood pressure while diminishing the tone of the heart muscle.

And there is more. Overexposure to cortisol is known to inhibit bone-forming cells causing osteoporosis.[10][11] The effects of excess cortisol were derived from studies on patients with Cushing’s disease: an adrenal gland disorder that triggers the release of abnormally high levels of cortisol. (Fig 7). Afflicted patients, exhibit a cluster of debilitating symptoms. Prominent among them are hypertension, hyperglycemia, high cholesterol, obesity and collagen fiber weakness.

Exposure to high cortisol levels damages the cells within the hippocampal region of the brain resulting in learning disability, memory loss and possibly Alzheimer’s.[12] Fig 8.

Abnormally high cortisol decreases skeletal muscle mass and suppress thyroid function. Although not life threatening, thyroid underactivity adversely affects several systems including the endocrine, reproductive, integumentary and central nervous systems. (Fig 9)

Mental Health

Unquestionably, physical exercise/activity preserves mental wellbeing. Done regularly, exercise oxygenates the brain and improves sleep. It increases proliferation of new brain cells, slows down brain cell aging and increases amounts of circulating neurotransmitters. Higher circulating levels of the neurotransmitter dopamine, improves mood and provides an overall positive feeling. Deficiency on the other hand is associated with fatigue, apathy, forgetfulness, moodiness, insomnia, concentration difficulty and lack of motivation.[13][14] Other neurotransmitters such as beta-endorphin and anandamide are usually elevated during intense exercise and induces a feeling of euphoria. Furthermore, exercise has been shown to reduce symptoms in people suffering from anxiety. [15][16]

Alzheimer’s Disease

Studies have demonstrated that people who exercise regularly were less likely to develop dementia.[17] Alzheimer’s is neurodegenerative disease which destroys the neurons of the hippocampus - the area of the brain that responsible for memory management and the ability to feel and express emotions.[18] In Alzheimer’s patients, the area of the brain associated with memory (hippocampus) is has shrunk markedly (Fig 10). But there are lifestyle practices that do prevent this outcome. For example, sustained physical activity mitigates the risk factors: they include hypertension, diabetes, and high cholesterol and obesity. As suggested, physical exertion increased the size of the hippocampus and strengthen the connections between the nerve cells in the brain. The net effect is memory augmentation and overall brain protection against injury and disease.[19] A study of the farming community of Ballabgarh, India, reinforces the point. Being farmers, the people are engaged in prolonged physical activity well into old age. In comparison to a community in Pennsylvania that carries the same Alzheimer’s gene (APOE), the Ballabgarh residents are unusually healthy despite the genetic similarity.[20] The findings indicate that by being physically active one can reduce these symptoms and prevent the untimely onset dementia.[21]

The Okinawans

The Japanese territory of Okinawa has a population of about 1.4 million inhabitants. Okinawans are the healthiest people on Earth: more people live to be over 100-years old than anywhere else. Not only do the residents have less cancer, heart disease, stroke and dementia than Americans, but Okinawan women have superseded the life expectancy of women globally. Of the myriad reasons adduced in support of their longevity, the commonest explanation is the physical activity of the people: they are active walkers and gardeners well into old age. [22] (Fig 11)

The Curse of Indolence

The Organization for Economic Co-operation and Development (OECD) estimates that 75% of the American population will likely be overweight/obese by 2020 and more than 85% of adults will be overweight/obese by 2030. Linked to obesity are increases in the risk of certain types of cancer, coronary artery disease, type 2 diabetes and stroke. Among industrialized countries, obesity rates in the US are the highest costing about $147 billion in additional medical expenses per year.[23]

A study by the Canadian Institute for Health Information and the Public Health Agency shows that over 25% of the population is overweight. The cost to the Canadian economy is about $11-billion annually. Similarly, the direct cost of treating obesity-related diseases is estimated to cost Australia $21 billion by 2025.[24]

Overall, it would seem that the impact of inactivity on the health and financial cost to the individual is unsustainable; that the benefits of activity supersedes that of inactivity; that indolence is the repose of fools. The data vindicates the observation of Thomas Alva Edison: The perils of overwork are slight compared with the dangers of inactivity.

To believe that entropy is an abstruse universal law of no personal relevance is to engage in a futile exercise of self-deception. That our bodies disintegrate with time is ample evidence; that all objects naturally degenerate and never the reverse is proof adequate. Rather than question the validity of this natural law, the more pragmatic approach would be to cultivate a strategy to counter its adverse effects. Fortunately, a resource capable of counterbalancing this destructive principle of spontaneous disorder does exist. It is called human effort: the reason that unrelenting human activity is a necessary component of daily living. Or, as the Nike slogan urges: Just do it!