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It was the end of my sabbatical in Canada, and I was strolling around Stanley Park, one of the many jewels of Vancouver British Columbia. I was just finishing a four month trip in Australia and Canada studying educational methods used to teach general practitioners. OK I'll come clean—I was having an “extended holiday with a purpose”. On this beautiful autumnal Sunday, the air was crisp and, as the sun sparkled on Burrard Inlet, the colours of the spruce, maple, and arbutus painted the lower slopes of the snow clad peaks across the bay. “No wonder this is one of the most popular places to live in our world” I thought.
Despite this idyll most of the people I saw that day looked ill at ease, in pain even. Why? I hear you ask. The answer is obvious: they were jogging! Why is an activity that is so blatantly uncomfortable so universally popular? At least it is good for them I thought.
Weeks later I was idly sharing these observations with a friend. He asked casually for another example of a bodily system that functions better when systematically stressed over a long period of time. I struggled for an answer. I was left wondering if jogging was a joke—at least in health terms anyway.
The World Health Organisation1 made the observation that jogging reduces health care costs, work absenteeism, and even increases productivity. So it's good for your boss and the government at any rate. How reliable are these statements? As in many WHO documents, this is not specifically discussed. Certainly, being very active seems to alter your lipid profile favourably (raised HDL, lower VLDL and triglyceride levels, possibly lower LDL levels).2,3 International athletes, however, have the same life expectancy as the rest of us, so what level of exercise are we talking about? The national runners health study4 suggests that, to achieve significant cardiovascular benefits, the jogger needs regularly to run in excess of 64 km a week or 7 miles a day. This means that the joggers in Stanley Park would have to do their run daily. Perhaps they do. A primary care study in the United Kingdom5 showed significant reductions in the death rate with a lifelong exercise programme. However, this programme had to include vigorous exercise starting in the 15–25 year age range, and the study numbers were small. Farrell et al6 showed that jogging, in the absence of other risk factors (smoking, hypertension, abnormal lipid profile), had the potential to achieve a 30% reduction in cardiovascular disease risk. However, if the jogger smokes, the level of exercise required to lower the risk rises dramatically, and if hypertension is present, then the gain is not significant at any level of exercise.
I keep telling my marathon running colleague that I have his NHS wheelchair on order, and the studies suggest that I may not be wrong. Knee pain has been shown to correlate with total “jogging years” and hours a week.7 Lifelong jogging increases the chances of making friends with your local orthopaedic surgeon,7,8 and that is without the increased risk of stress fractures and minor orthopaedic complaints. The literature is full of the hazards of urban jogging; if the traffic doesn't get you, the pollution might. There is a possible link between urban ozone levels and lung inflammation.14
Unfortunately, the evidence that joggers are at least strengthening their bones is also equivocal. Although bone density at the hip may increase, no reduction in osteoporotic related fractures has been shown.10 If all that's not enough, a Swedish study11 has shown an increased risk of arrhythmia in elderly male joggers (average age 73.2 years). The potential for sudden death during jogging is well documented and probably represents a cardiovascular event. There has also been some suggestion that too much jogging can actually impair the immune system and increase the incidence of minor infection, although this seems to be speculative. Some runners report an improvement in visual acuity during exercise (so perhaps these Canadians can see their mountains more clearly than I), but this seems to be a subjective experience (they only think they can see them more clearly), and, except for perhaps a small reduction in intraocular pressure, no effects on the eye are apparent.12,13 There is a report of some improvement in the symptoms of diverticular disease after jogging,14 although I doubt many joggers have this in mind as they don their trainers. And then there is joggers nipple, but we won't dwell on that!
Now you may have formed the impression that I don't jog, and you would be mostly right. I'm certainly not a habitual jogger, although I do dabble occasionally. I still feel that man is essentially a Stone Age animal living in the modern world. For the life of me, I can't imagine Stone Age man jogging. Running like hell to escape a snack-seeking carnivore: yes. Strolling along collecting berries: yes. Jogging: I just can't see it. It seems so unnatural.
So how do I feel about my jogging compatriots? I still have this deeply British admiration for the “no pain, no gain” philosophy. Mostly I hope the joggers do enjoy running (but I do wish they'd smile). I will continue to extol the virtues of the healthy lifestyle to my patients, and I'm sure exercise is in there somewhere. However, I'm not convinced that the joggers will need my services any less than my “normal” patients—whoever they are!
Now—anyone fancy a nice walk?
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