Why I study... the effects of exercise

When I sat down to write this article, my mind immediately regressed back to my childhood. I recalled an LP of songs from the 1970s children's television programme The Wombles that I was given for my third birthday. One of the tracks went something like…Standing on your tiptoes
Running on the spot
Exercise is good for you
Laziness is not
Maybe deep down, the wise words of the Wombles were the spark for my professional interest in the benefits of exercise.
The physical benefits of exercise have of course long been known; and today we know much more about the specific benefits of physical activity, thanks in part to the pioneering work of Professor Jerry Morris (Morris et al., 1953), who demonstrated an association between physical activity and coronary heart disease. But what has caught my imagination over the years are the many quality of life and mental health benefits that appear to result from participation in regular exercise.
During my training I spent some time with psychiatric outpatients, and I got involved in 'walk and talk' sessions with a patient who was experiencing quite complex emotional issues in her life. This patient (whom I will call Lucy) responded well to notion of 'exercise as a therapy' and she was keen to receive support in this way. I have described my experiences elsewhere (Daley, 2002): after the 12-week exercise programme Lucy reported feeling better, and I remember she commented: 'I never would have thought someone like me would be able to do this [exercise].'
Well, if it's good enough for Nelson Mandela… In The Long Walk to Freedom, Mandela makes a number of references to participating in exercise during his imprisonment and comments 'exercise dissipates tension, and tension is the enemy of serenity'. He also comments:
I did manage to influence some of my more sedentary colleagues. Exercise was unusual for African men of my age and generation. After a while even Walter [Sisulu] began to take a few turns around the courtyard in the morning. I know that some of my younger comrades looked at me and said to themselves 'if that old man can do it, why can't I?' They too began to exercise.
These stories and experiences are well supported by epidemiological and randomised controlled evidence, particularly by the At Least Five A Week Report from the Chief Medical Officer (Department of Health, 2004). Further, the National Institute for Clinical Excellence (2004) recently endorsed the use of exercise as a primary treatment for mild to moderate depression. Innovative pilot trials (Armstrong & Edwards, 2003, 2004) conducted in Australia have also found that exercise is a useful adjunctive treatment for postnatal depression, and these studies have recently prompted me to pursue this question further within my own programme of research.
My early experiences in psychiatric outpatients sparked a desire to further test the health benefits of exercise in a more controlled and systematic fashion in different patient groups. Indeed, much of the early evidence about the benefits of exercise was based on general population evidence rather than clinical groups. During the 1990s I stumbled across the research of Professor Kerry Courneya, who has developed an impressive programme of research in Canada that focuses on the benefits of exercise on quality of life, functioning and feelings of fatigue in cancer patients. Courneya's work has contributed significantly to systematic reviews and meta-analyses (Knols et al., 2005; Stevinson et al., 2004) in this field, which have concluded that participation in regular physical activity is likely to provide important benefits both during and after treatment for cancer.
In practice, this has provided an interesting dilemma for clinicians and health professionals, since a common medical theme of the past has been that 'rest is best' – that chronic diseased patients should concentrate on conserving, and not expending energy. How we reconcile these opposing health beliefs is an important question that we need to continue to address.
A recent trial (Dunn et al., 2005) reported that exercise by itself is effective in the treatment of mild to moderate depressive disorder. So, if we accept that exercise is indeed good for us and laziness is not, the next questions are Why does exercise make us feel good? and How much do we need to do to benefit? Unfortunately, I think it fair to say that we don't really have the answers to Why? since most research has focused on effects rather than the mechanisms and causes.
I have also been guilty of this emphasis, but I am trying to change my ways, and have recently completed two trials involving obese children and women treated for breast cancer that attempted to tease out the 'real' quality of life benefits of aerobic exercise from the possible social/attentional effects associated with participation. I am fortunate that I work in a Department of Primary Care and General Practice, so I have access to lots of different clinical populations on which to test my hypotheses regarding exercise.
In research terms we are still faced with the problem of how to best motivate people to adhere to participation in regular exercise. A phrase I have heard many times is 'If exercise could be taken as a pill, everyone would be on it' – something of a double-edged sword since on the one hand it highlights that we recognise the benefits of exercise, but that we do not want to exert any effort in reaping those rewards. For many this is understandable: imagine for a moment you are depressed, isolated, feeling alone and barely able to motivate yourself to perform everyday tasks such as washing and eating, or you are recovering from a cycle of chemotherapy and are feeling sick, fatigued and wondering whether you will be alive in six months' time. Irrespective of how committed or motivated you might be, exercise is probably the furthest thing from your mind. It is easy to see then how people might believe rest is indeed best. I don't have the answers, other than to say that patients who are able to find the strength to participate in exercise (despite their difficulties) report feeling better afterwards. I am sure the pursuit of some of the answers to these questions will keep me busy for the rest of my research career, and they certainly do a good job now of motivating me to get out of bed in the morning.
Back to the Wombles, who were not only wise in their judgements about exercise, but were keen on 'making good use of the things that we find'. I also hope to make good use of the things I find in my research – I would like to contribute to the evidence base by conducting high-quality clinical trials so that we are better able to understand the efficacy and effectiveness of exercise for health benefits. Over time I hope this will translate into action through the routine promotion of exercise in different contexts for both the population as a whole, as well as clinical groups.

Dr Amanda Daley is in the Department of Primary Care and General Practice, Medical School, University of Birmingham. E-mail: [email protected].

Weblinks
Chief Medical Officer's 'at least five a week' report: tinyurl.com/tk6tc
behappybehealthy: www.behappybehealthy.co.uk
The British Association of Sport and Exercise
Sciences: www.bases.org.uk/newsite/home.asp

References

Armstrong, K. & Edwards, H. (2003). The effects of exercise and social support on mothers reporting depressive symptoms: A pilot randomized controlled trial. International Journal of Mental Health Nursing, 12, 130–138.
Armstrong, K. & Edwards, H. (2004). The effectiveness of a pram-walking exercise programme in reducing depressive symptomatology for postnatal women. International Journal of Nursing Practice, 10, 177–194.
Daley, A.J. (2002). Exercise therapy and mental health in clinical populations: Is exercise therapy a worthwhile intervention? Advances in Psychiatric Treatment, 8, 262–270.
Department of Health (2004). At least five a week: Evidence on the impact of physical activity and its relationship to health. London: Author.
Dunn, A.L., Trivedi, H., Kampert, J.B. et al. (2005). Exercise treatment for depression: Efficacy and dose response. American Journal of Preventive Medicine, 28, 1–8.
Knols, R., Aaronson, N.A., Uebelhart, D., Fransen, J. et al. (2005). Physical exercise in cancer patients during and after medical treatment: a systematic review of randomized and controlled clinical trials. Journal of Clinical Oncology, 23, 3830–3842.
Morris, J.N., Heady, J.A, Raffle, P.A.B., Roberts, C.G. & Parks, J.W. (1953). Coronary heart disease and physical activity of work. Lancet, 2, 1111–1120.
National Institute for Clinical Excellence (2004). Depression: Management of depression in primary and secondary care. National Clinical Practice Guideline No.23. Leicester/ London: British Psychological Society and Gaskell.
Stevinson, C., Lawlor, D.A. & Fox, K.R. (2004). Exercise interventions for cancer patients: systematic review of controlled clinical trials. Cancer Causes Control, 15, 1035–1056.