Does exercising distance us from dying? Intuitively, there is no doubt. But does is really it ensure a longer life? It is still unclear. We will review the medical studies accumulated, examining the relationship between fitness and mortality, and additionally, life expectancy and quality of life.
By Baruch Weinshelboym
One result of the advancement of technology, which began with the Industrial Revolution, is that people in general enjoy higher standards of living and have longer life expectancies. But this so-called progress has also been accompanied by an increase in frequency of "hypokinetic" diseases (lessened movement) that ironically lead to accelerated characteristics of aging and possible faster wear of the organs and tissues in the body. The main systems that would be adversely affected as a direct result of lessened movement are the cardiovascular, blood and musculoskeletal systems.
In recent years, there has been a drastic increase in the awareness of the health benefits of constant engagement in physical activity. This recognition has led to an increase in the number of exercise participants in virtually all age groups - both young and elderly - but unfortunately, not yet in the optimal frequency. In the US and Canada, about 50% of the adult population does not exercise adequately to meet the recommendations of the various health care organizations. In Israel, the numbers are quite similar to the rest of the Western world.
Lack of exercise typically doubles the chance of coronary heart disease and is a major risk factor contributing to serious chronic diseases, such as diabetes, breast and colon cancer, obesity, hypertension, and diseases of bones and joints (osteoporosis, osteoarthritis), anxiety and depression, and the risk of falls for elders. A "sedentary" lifestyle, the lack of sufficient movement, has been identified by WHO as the leading cause for preventable mortality. This brief article will review the current knowledge in the scientific literature concerning the relationship between physical activity and mortality, life expectancy and quality of life.
Relationship between exercise and mortality
Back in the 50s and 70s of the last century, evidence from a number of longitudinal cohort studies suggested that men and women who increased their physical activity reduced the relative risk of mortality by around 20-35%. Recent studies show an even higher decline in mortality risk in cases of people who have elevated themselves to a higher level of physical fitness, and in some cases there is evidence of a decline of more than 50% in the risk of death.
In addition, exercising at a rate of burning 1,000 calories a week or alternatively improving the aerobic fitness by 1 MET (the amount of oxygen the body consumes per kg per minute) caused a significant reduction, of around 20%, in the risk of death.
A middle age woman that is not active (defined as at least an hour per week) has a 52% higher chance of death generally, has double the risk from dying from heart and vascular diseases, and a 29% chance of death from cancer, when compared to women at the same age who exercise. The significance of these findings is that the health of a healthy woman that does not exercise is similar to the health of a person suffering from high blood pressure, high cholesterol, obesity or smoking cigarettes at an intermediate level.
Conversely, the health benefits of exercising have been reported amongst cardiac patients. In research encompassing the results of 48 experimental studies on the physical rehabilitation of heart patients, there was a significant decrease in the incidence of early mortality from all causes, particularly heart disease, in heart patients who exercised regularly.
Burning 1600 calories weekly in physical activity halts the progression of coronary heart disease, and burning 2,200 weekly is related to lowering vascular atherosclerotic plaques. Low intensity exercise (less than 45% of maximum aerobic capacity) contributes to improving the health state of patients with heart disease
Life expectancy and quality of life
In general, there is very little evidence supporting increased life expectancy as a result of regular exercise. However, there is some scientific data that shows that chronic physical activity moderately increases life expectancy. Paffenbarger Research conducted in 1986 found that among people aged 80 who engaged in regular physical activity burning more than 2,000 a week, there was an increase in life expectancy of 1-2 years.
In the more recent study noted above, the relationship between running and high life expectancy was illustrated.
In addition, there is ample evidence that suggests physical activity improves the quality of life, especially in adults. Aging leads to a phenomenon called "Sarcopenia" (decrease in the size and number of muscle cells = decrease in muscle mass). The process is biological, normal and happens to all of us at different rates. As a result of these processes, it is difficult to perform basic daily tasks at a later age, because of strength and muscle mass limitations.
Exercise is very important for maintaining the physiological reserves of aerobic fitness (cardio) and the functioning of the musculoskeletal system. Physical activity can not completely stop the biological process of aging, but its greatest benefit is that is slows down the rate of decline in our physical abilities and moderates the effects of aging on different functions.
A person exercising regularly assures himself of accumulating reserves of various systems that are ordinarily destroyed with aging. Recent studies have found that physical activity is contributing to non-dependent functioning, mobility, balanced sugar levels in the blood, bone health, mood, psychological stability and improvement in quality of life. Also, it has led to a decrease in the incidence of falls, illness and premature death.
When dealing with life expectancy, it should also be mentioned that exercise protects one from serious diseases, and indirectly contributes to a longer life.
Baruch Weinshelboym - M.Pe Physical Education Sciences, specializing in the physiology of strenuous activity, speaker at the sports and recreation club at Wingate, and a veteran in the Even Yehuda branch.