Why Physical Activity Should Be Vital in Public Health Policy

Back in the 1980s, Dr. Robert Butler, director of the American Institute on Aging, stated that "If exercise and physical activity could be packaged as a pill, it would be the single most widely prescribed and beneficial medicine in the nation." Although many questions remain about the mechanisms of effect and optimal modalities, a synthesis of the literature indicates many positive effects of participation in physical activity on the aging process and mortality with dose-response curves indicating benefits are linked to both intensities and volumes of exercise.

Since then, the World Health Organization (WHO) has repeatedly confirmed that physical inactivity and a sedentary lifestyle worsen chronic health problems, including hypertension, cardiovascular and cerebrovascular diseases, diabetes, depression, and dementia. Indeed, estimates from 2012 indicated that not meeting physical activity recommendations is responsible for more than 5 million deaths globally each year. To top it all, it has been proven that reducing the number of daily steps for 14 days is enough to increase the risk of future metabolic disease and insulin resistance, typical of type II diabetes and obesity.

Our Bodies Are Designed to Move

It is confirmed that we are designed to move and that if we don't, the burden of disease and mortality will skyrocket exponentially. In the world population, however, only 18% of adults aged 65 to 74, and 15% of those over 75, meet the minimum recommendations for physical activity of 150 minutes of moderate-vigorous physical activity weekly and muscle-strengthening exercises at least twice a week. But what is really worrying is that this "deficiency in the practice of physical activity" is observed from the first stages of life. It is the real problem that causes childhood obesity. If Dr. Butler raised his head 33 years later, he would confirm what he already suspected: physical activity and sport should be essential activities in public health policy, and more so during the pandemic.

Despite the great advances in science at the moment, there are no drugs (or combinations) that can improve physical capacity in people, and none will likely be developed in the foreseeable future. The evidence on the positive effects of physical exercise has led it to equate it to the best of medicines. It must be recognized, however, that not all drugs cure cancer, nor do all types of exercise (cardiovascular, muscle-strengthening, balance) have the same effects on disease and functional capacity. Walking is not enough and it is not advisable to follow some of the YouTube trends by influencers wearing tracksuits. Evidence-based interventions on physical activity should play a key role in medical care and public health.

Physical Activity Should Be Essential in Public Health

Exercise has not been fully integrated into the routine practice of primary or geriatric medicine and is still practically absent from the basic training of most physicians and other healthcare professionals. It is something that COVID-19 has made more evident, both in those who practice little physical activity and those who carry the long-term effects of COVID, and has become increasingly clear that physical activity needs to play a central role in recovering.

Dose-response heterogeneity is not unique to pharmaceutical therapies. In the era of precision medicine, interindividual variability in the magnitude of response to supervised exercise training (subject-by-training interaction or individual response) has received increasing scientific interest in both adults and children. For instance, some individuals show improvements with exercise training (e.g., decrease in fasting glucose) and are considered responders, whereas others may not have such a response (e.g., no change or even increases in fasting glucose) and are considered non-responders.

Exercise and medical researchers have recognized the substantial variability in patient response to physical exercise interventions and have sought to understand these differences. Individual interaction of physiological, molecular (i.e. genetics, epigenetics, transcriptomics, and metabolic factors), and environmental factors are being investigated as potential mediators in the lack of response to exercise in some participants. Today, at the dawn of an unprecedented new era of scientific discoveries where especially precision medicine is advancing the individualized treatment of diseases and even the improvement of life expectancy, we must not forget the simple and important message: exercise is not just for children and younger adults, older people can adapt to exercise and deserve to benefit from it. It is never too late, and you are never too old to contract your muscles. In addition, physical exercise is also the only cheap, effective, and safe "vaccine" without supply problems, queues, or shifts, that everyone can start taking right this moment.

Understanding and Designing Exercise Programs

Now, it is also becoming clear that more research is needed on exercise interventions for older adults, the ones largely overlooked in medical studies. Important questions remain about the safety, efficacy, and inherent variability between people in response to exercise. Understanding this variability is essential to identify the best treatment method (simple exercises or multi-component exercises) and intensity (low, moderate, or high-intensity resistance exercises) to preserve and ideally improve physical capacity in very advanced ages. Aside from being safe for healthy older adults, a properly designed resistance exercise is relatively free of potential unwanted side effects caused by common medications prescribed in patients with multiple comorbidities.

The essential fact is that more actions to promote a positive health culture should be identified. Physicians in almost all specialties, but especially those in primary care and geriatrics, should advise all patients, regardless of age, to be as active as possible. General practitioners should play a key role in counseling and appropriately referring their patients to incorporate physical activity. Medical schools should teach students that skeletal muscle remains adaptable tissue throughout human life.

Physical fitness service providers should also be included in the healthcare system to help plan and implement physical exercise programs for patients. The practice of physical activity and physical educators should have a more relevant role in solving this problem. This will be one of the great pending challenges for public health in the coming years.