FOR the past 20 years our team at the Edith Cowan University Health and Wellness Institute has been researching and applying an exquisite medicine.
This medicine prevents, ameliorates and, in some cases, cures most chronic diseases. If prescribed and administered correctly this medicine has no side effects. This medicine is exercise.
It is important to differentiate between physical activity and exercise. The WHO defines physical activity as “any bodily movement produced by skeletal muscles that requires energy expenditure”.
The WHO is explicit that the term “physical activity” should not be used interchangeably with exercise: “Exercise, is a subcategory of physical activity that is planned, structured, repetitive, and purposeful in the sense that the improvement or maintenance of one or more components of physical fitness is the objective.”
Increasingly, world authorities such as the American College of Sports Medicine and Exercise and Sports Science Australia are using the term “exercise medicine” to refer to exercise that is specifically prescribed to treat diagnosed illnesses.
Our predominant focus of research for the past 10 years has been the application of specific exercise for the management of patients diagnosed with cancer.
Retrospective studies conclude that cancer survivors who meet a relatively modest level of physical activity reduce their risk of all-cause mortality and cancer-specific death by between 50% and 60%.
The effectiveness of exercise as medicine to positively impact tumour biology can be explained by a range of mechanisms such as altered myokine/adipokine profile, improved immune function, lowered systemic inflammation, epigenetic modulation, reduced fat and increased muscle mass and activation, reduced cholesterol, hormonal changes and improved insulin sensitivity and glucose regulation.
There is something really exciting about the alterations in systemic chemistry that occurs as a result of acute and chronic exercise. One in vitro study reported that exposing prostate cancer cell lines to the serum of humans who had undertaken exercise caused a 31% reduction of tumour cell growth.
Our group has also previously reported on decreased levels of C-reactive protein following 12 weeks of exercise in men treated with androgen deprivation therapy for prostate cancer.
The rapidly growing body of research demonstrates that exercise is not only essential for maintenance of health and prevention of disease but also a highly effective treatment for the chronic diseases that are causing the greatest morbidity and mortality.
It is important to note that exercise is not a single medicine. Different modes (aerobic, resistance, continuous, intermittent) and dosages (volume, intensity, rest interval) impact entirely different body systems and produce markedly varied physiological responses and adaptations. For example, aerobic exercise produces adaptations in the cardiorespiratory system while resistance exercise stimulates positive changes in the muscular and skeletal systems.
One of the issues often raised by medical practitioners regarding prescription of exercise for chronic disease management is that of compliance. Compliance to supervised exercise medicine is about 75%‒ 85% at 6 months and 65% at 12 months. This more than favourably compares with patient compliance to pharmaceutical therapies. For example, it is reported that only 50% of patients will be compliant with their statin therapy at 12 months.
The level of compliance and broad physical and psychological benefits resulting from exercise are quite astounding given the limited support available to patients and the considerable barriers that they face in implementing and maintaining exercise.
The situation is improving with an increasing number of accredited exercise physiologists (AEPs) seeing patients and their services, now Medicare rebated under the chronic disease management item. AEPs are the most appropriate allied health professionals to assess and prescribe exercise for the management of chronic disease, and GPs are increasingly referring patients to this valuable professional resource.
Exercise is possibly the most powerful medicine currently known and is unlikely to be superseded regardless of advances in medical science.
Traditional medical management of patients is essential and exercise will never supplant pharmaceutical therapies. However, arguably most chronic diseases are, in part, a result of chronically low levels of physical activity and exercise should be prescribed as a frontline therapy equal to other treatments.
Professor Robert Newton and Professor Daniel Galvão are co-directors of the Edith Cowan University Health and Wellness Institute in WA. Professor Newton and Professor Galvão are also professors of exercise and sports science at Edith Cowan University.