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1 Why research into health and physical activity?
Stephen R.Bird
In developed countries the prevalence of non-communicable diseases such as cardiovascular disease (CVD) and type 2 diabetes (T2D) has increased substantially during the past 50 years.1,2 A recognized factor contributing to the increase in these diseases is the reduction in the amount of physical activity undertaken on a daily basis by many people today compared with previous generations.3 The proposed reasons for this include but are not limited to: (i) the mechanization of many jobs, which has resulted in a reduction in occupational physical activity and a shift towards more desk-based, sedentary occupations;4 (ii) a reduction in incidental physical activity, where again mechanization has reduced the physical demands of household tasks and gardening; (iii) a reduction in active transport, with fewer people walking or cycling to work and other locations, but tending to use motorized transport; and (iv) an increase in sedentary leisure pastimes, such as television and other âscreen timeâ pursuits, over hobbies and interests that involve more physical activity. Hence whereas in previous generations physical activity was inherent within the lifestyle of most people, it is no longer the case. This trend towards less activity and the associated increase in the aforementioned chronic diseases has led them to be termed as âhypokinetic diseasesâ. The incidence of many of these conditions is further exacerbated by changes in the availability of high-caloric foods and refined sugars that result in food intakes that exceed daily caloric expenditure (hyper-caloric). This combination of hypo-activity and hyper-caloric intakes contributes to the prevalence of obesity and many of the other risk factors associated with the chronic diseases that are now so prevalent.5â7
Other factors that have contributed to the recent increased prevalence of chronic diseases include improvements in surgery and the medical treatment of infectious diseases. As these have increased survival rates for trauma and infections that were previously fatal, and as a consequence, people are now living longer and becoming more susceptible to the aforementioned hypokinetic diseases and conditions that develop over a prolonged period of time. An additional consequence of more people living to an older age is an increase in the prevalence of conditions that are associated with ageing, such as dementia, osteoporosis and sarcopenia. The prevalences of which are exacerbated by lifestyles that lack the physical activity known to ameliorate the development of these diseases.8â10 Hence, whilst there are many factors contributing to the increased prevalence of the aforementioned chronic diseases and conditions, insufficient physical activity is a consistent factor throughout.
These chronic conditions have adverse effects upon the health, functional capacity and quality of life of the individual sufferers as well as affecting their families and placing a considerable burden upon the healthcare services that support them. Critically, it has been suggested that if we donât improve the health of the population, we face the prospect of an ageing society with a high prevalence of people with chronic disease and a shortage in the healthcare workforce that will be needed to look after them. Consequently, strategies and interventions that can prevent and alleviate these conditions have significant physical, mental, social and economic benefits.
The role of physical activity in reducing the risk of these diseases began to gain prominence in the research literature over 50 years ago, through the seminal research of Jerry Morris and Ralf Paffenbarger amongst others.11â14 Building on this early scientific evidence, the case for the benefits of physical activity has continually been strengthened and broadened through the results of thousands of subsequent studies. Accordingly, physical activity is now recognized as an important factor that can benefit many aspects of physical and mental health, whilst inactivity and sedentary behaviour are recognized as significant health risks. Since as previously indicated, physical activity is no longer inherent within the lifestyles of many people, it now needs to be purposely added through the inclusion of deliberate exercise of some form. This has led to governments and health authorities promoting physical activity as a preventative measure against many diseases, as a means of recovery from many diseases and for secondary prevention (the treatment of the disease to reverse its effects and/or prevent or minimise its exacerbation). Although at this point it is worth acknowledging that whilst physical activity guidelines tend to focus on meeting physical activity targets in terms of minutes and sessions per week, there is some debate about whether it is the amount of physical activity thatâs undertaken on a regular basis, or physical fitness, thatâs quintessential to the attainment of good health and reduction of disease risk.15 Inevitably there is a link between physical activity and fitness, but the distinction should be remembered.
The physical activity guidelines produced by governments and august bodies have been founded upon the knowledge gained from high-quality research that has endeavoured to identify: the physical, mental and social benefits of physical activity; the key risk factors associated with inactivity; the details for optimal exercise prescription; the factors that can facilitate participation in physical activity; and how to achieve effective lifestyle change. This research needs to continue, since whilst it is well established that âexercise is good for youâ, determining the optimal type, frequency, duration, intensity and timing of the physical activity for each individual, as well as how it interacts with other lifestyle components such as nutrition, requires further elucidation, as do the precise mental, metabolic and physical responses and adaptations to physical activity. Furthermore, despite the overwhelming acceptance of the importance of physical activity, the majority of adults in many countries fail to achieve the minimum requirements for good health,16 and hence research that can guide and inform effective behaviour change continues to be of vital importance. The need for ongoing, current research into physical activity and health will always be necessary as the society in which people live is subject to continual change. For example, some of the current impediments to being physically active were not an issue or even in existence a generation ago. Including the aforementioned decline in occupations that require physical activity, the reduction in active transport, and the increase in sedentary leisure pursuits (television and other screen time). Similarly, some of the current means for encouraging and promoting physical activity, such as social media, GPS watches and computer-interfaced software support programmes, were also not in existence a few years ago, and have therefore warranted the attention of current researchers. Future developments in information and communication technologies will thereby continue to present new challenges and opportunities for future generations of researchers. In parallel with this, there have been extraordinary developments in techniques and equipment for measuring physiological, metabolic, molecular and other aspects of the body, which have increased our knowledge of how the body works. This means that health and physical activity studies can now measure adaptations and responses in ways that were previously inconceivable, thereby presenting the opportunity for research studies to investigate in greater detail the issues of health and physical activity. Nevertheless, these ground-breaking techniques will only produce valid data if the basic principles behind physical activity research are adhered to. This means that even in studies where the latest equipment and techniques are being used, components of the study design, such as the process for participant recruitment, screening, compliance, control of confounding factors and many other aspects, must be considered carefully.
Furthermore, ongoing technological developments provide opportunities for researchers in other ways as they enable sophisticated data analyses on personal devices that previously would have had to have been undertaken by hand, which in many cases was not feasible. This has thereby enabled the design and analysis of studies with larger data sets and more factors to be assessed in ways that were not previously possible, as illustrated by the interest in interrogating âBig Dataâ. Even at a much more basic level it is interesting to compare the lack of mention of checks for statistical violations, normality, sphericity and power analyses in many of the research papers published 40 years ago, whereas these are now a common expectation of undergraduate projects. Likewise in the fields of qualitative research, technological developments have facilitated new, innovative and effective ways to collect, analyse and interpret data. Additionally, access to these technologies and sophisticated analysis programmes has enabled the findings of previous studies to be re-evaluated, the data interrogated in greater depth and for the interaction between, and influence of, many more factors to be included in ways that were not previously possible.
For the researcher the ultimate goal must be to have an impact that in some way benefits the health of individuals and society. Measures of this impact and benefit are recognized through their inclusion in the assessment of research grant applications, reviews for publication and research ratings. If we are successful and our findings are translated into policy and action, the impact on society will be dramatic. Indeed, the established benefits of physical activity are plentiful and as former American College of Sports Medicine president Robert Sallis stated at the launch of the âExercise is Medicineâ initiative on 5 November 2007: âif we had a pill that conferred all the proven health benefits of exercise, physicians would widely prescribe it to their patients and our healthcare system would see to it that every patient had access to this wonder drug â.17 a point concurred upon by Jerry Morris in the context of cardiovascular disease when he described exercise as public healthâs âbest buyâ.18
Another challenge facing current and future generations of researchers is that the general public are continually bombarded with a plethora of unfounded claims and the marketing of diets and interventions that have no evidence for their health benefits or effectiveness. The nature of these are often attractive to those seeking a quick fix without the need for commitment and effort. Something that is exemplified by regular features in the media on progress towards the âexercise pillâ. However, given the breadth of health benefits conveyed by physical activity it is difficult to envisage how a pill could deliver all the positive responses and adaptations. Furthermore, as discussed by Hawley and Holloszy, âwhy search for a pill when exercise with all its diverse beneficial health benefits is so readily availableâ.19 Hence our current and future generations of physical activity researchers need to continue to present unbiased evidence from high-quality research studies, and those involved in the promotion of health and physical activity need to have the skills to identify high-quality evidence from that which is flawed and biased. They will also need to interpret potentially complex issues and disseminate the key health messages to the general public in a clear and informative manner. This is a real challenge given the nature of science as illustrated in the quote attributed to Carl Sagan:
Finding the occasional straw of truth awash in a great ocean of confusion and bamboozle requires intelligence, vigilance, dedication, and courage. But if we donât practice these tough habits of thought, we cannot hope to solve the truly serious problems that face us â and we risk becoming a nation of suckers, up for grabs by the next charlatan who comes along.20
This nicely encapsulates the issues facing the researcher and the context in which research needs to be undertaken to identify what physical activity is beneficial to health and to refute claims that have no scientific basis. Furthermore, whilst much research has tended to focus on the benefits of physical activity for the prevention of âill-healthâ, researchers also need to consider the role of physical activity in promoting good health, beyond âbeing just simply free from diseaseâ, as emphasized in the WHO definition.21
The popularity of university programmes in this field of exercise and health, as well as the inclusion of physical activity modules in the studies of other allied health professionals, reflects the current recognition of the importance of physical activity. Likewise the inclusion of research methods in the undergraduate and post-graduate curricula of many health-related degree programmes reflects the recognized needs of the future health workforce. A physical activity and health workforce and the research students who will become the elite researchers of the future, who can understand, participate in and contribute to high-quality research in this field is of vital importance. Beyond undergraduate programmes and in the wider context, âPhysical Activity and Health Researchâ is conducted by health researchers and their colleagues based in hospitals, research institutes and universities. The nature of such research, involving human participants, means that the design of studies that utilize the most appropriate research methods is paramount for the production of high-quality research, and must withstand the rigorous scrutiny of ethics committees and funding bodies. Hence a strong knowledge and understanding of research methods is essential for both established researchers and those early in their research career who will need to collaborate and undertake multi-disciplinary research that may require extending their existing expertise into related but less familiar methods and paradigms. The purpose of this text is therefore to provide researchers of all levels with an insight into research techniques, processes and the issues of working with different groups. For those who are early in their research careers it seeks to provide a broad coverage of and introduction to research methods in our field, whilst for more experienced researchers it may provide a new awareness of methods that they may not have used previously and specific considerations that are pertinent when working with different groups, who they may not previously be familiar with. The text has been written to enable readers to dip into specific chapters and then pursue the topic in greater depth or breadth if required, by referring to the referenced literature. To conclude, this text aims to contribute to the pursuit of high-quality research studies that will inform future policy and exercise prescription for the improvement of health. Iâm sure that I can speak on behalf of all the authors by w...
