Can jogging kill?

Press, 16 February 1980, Page 15

Can jogging kill?

Heart disease is the greatest killer in the western world. In Britain' alone, more than 500 people die every day from heart-related ailments. The conventional wisdom is that regular vigorous exercise can stave off heart disease, and during the 1970 s — dubbed “the intensive care decade” because of the popular obsession with health — jogging' became the most common and most publicised way of pursuing fitness and longer life. Running for health is so popular that , the spectacle of thousands of happy joggers setting off on mass “fun runs” is now commonplace. Annual runs in Australia and New Zealand attract up to 30.000 participants, while in Britain The “Sunday Times” National Fun Run, in its first two years, has drawn entries of 12,000 and nearly 16,000.

Yet there are doubts. Recent newspaper reports, under such alarming headlines as “Jogger dies” and England soccer doctor dies on exercise run” seem to suggest that violent exertion, far from being lifeenhancing, may be positively dangerous. The disturbing aspect of “jogging deaths” is that some victims have been men of athletic habits, regarded by others as being fitter than the average person. One such was the England football team’s doctor, 53-year-old Peter Burrows, generally considered to be a fitness fanatic —

training hard with the England squad, playing squash and jogging regularly. Yet on March 18 last year, Burrows died of a heart attack after covering only 200 yards of his regular run. Even more dramatic was the death of Dennis Stephenson, also 53. He had been an athlete all his life and was one of New’ Zealand’s leading distancerunners, holding records for 100 miles and 24-hour running. He suffered a fatal heart attack the day after competing in a marathon race.

In both these cases, however, the facts are more complicated than the headlines suggest. Although the victims appeared to be perfectly fit, post-mortem examinations showed that both were suffering from severe atherosclerosis: a build-up of fatty deposits in the coronary arteries.

Shortly before his death, Peter Burrows had noted warning signs, including chest pains and tiredness which interfered with his squash playing. Sometimes he would have to stop his car as he drove to his surgery. He took an electrocardiograph test, but no abnormality was shown, even when he ran up and down stairs in an unsuccessful attempt to reproduce the sort of pains he had suffered. Yet the disease was there, and it killed him.

Dennis Stephenson had also received physical warnings. During training runs he had complained of

dizziness; he had passed out during a university lecture; he had suffered pains in his chest and arms; and in the marathon the day before his death he had felt off colour and had completed the course in an extremely slow time. The first question that arises from the deaths of Burrows and Stephenson is: how can it be argued, that regular vigorous exer-’ cise staves off heart trouble when atherosclerosis killed two such athletic men at a comparatively early age? The answer seems to be that certain people are susceptible to heart disease no matter what they do, and that jogging does not necessarily outweigh risk factors such as a cho-lestrol-rich diet, heavy smoking, high blood pressure and stress. Peter Burrows described himself as a classic coronary case, his wife says. He had a volatile temperament and stress was part of his everyday life as a dedicated G.P.

“That’s why he took up serious exercise again in his late thirties,” Mrs Burrows says. “When he came home from surgery very tense and irritable, exercise was an escape valve, a means of relaxation, or comparative relaxation.” In the case of Dennis Stephenson, ' hypertension (high blood pressure) is thought to have been the underlying cause of his death. Dr Norman Sharpe, the Auckland Hospital cardiologist who studied the

autopsy on Stephenson, points out that hypertension is an organic disease which can start early in life, is not necessarily related to a person’s fitness, and is influenced by different factors in different individuals.

"If you take population groups you’ll find a much lower incidence of hypertension in fit people," says Sharpe. “But that

doesn’t necessarily hold true for any one individual. If someone is destined to have high blood pressure, as it seems Dennis was, then no amount of training is going to stop that completely — though it could dampen it doMm.” This prompts a second question. Given that Burrows and Stephenson were predisposed to atherosclerosis, did their ath-

letic activity on the day in question trigger their deaths? • At best the evidence is inconclusive, as pointed out by Dr Roy Shephard in the British Journal of Sports Medicine: "Many authors have found some relationship between physical activity and sudden death, but there is not complete unanimity on this association.” In his article, Shephard outlined good theoretical grounds for supposing that exercise can precipitate heart attack but found that the theory is not necessarily supported by studies of sudden deaths. Statistical evidence is slight. A Finnish study of 2600 sudden deaths established that a third of them were associated with physical or psychological stress: two of the victims had been jogging, 16 skiing and 67 taking a sauna. A smaller study in Toronto found that of 233 heart-attack deaths, a quarter were connected with physical activity, including walking (13 deaths), snow-shovelling (9), running (8), ice sports (4) and heavy domestic chores (15). Such figures suggest that even modest activity or stress can be fatal if certain conditions preexist, but it would be necessary to produce data about the number of people hourly engaged on various activities before a valid risk ratio could be established. One piece of negative statistical evidence is found in the. records of the fun runs in Australia and New Zealand, which — though they cover seven or eight miles and often involve novice runners — have never led to a fatality. As for the “Sunday Times” Fun Run, a calculation based on statistics for heart-related deaths in the UK each year indicates that one death in the event among men aged 45 : 64 would not be surprising. In fact just one “serious” incident has been reported by the attendant doctors and . the runner already had a medical condition for which he was being treated. What positive evidence there is tends to be in favour of exercise. Dr Terence Kavanagh, of Toronto, uses jogging as part of the rehabilitation

programme for cardiac patients. He reports that between 1968 and 1978 a total of 233” patients at his clinic logged nearly a million exercise miles and only 58 suffered second heart attacks. “These are high-risk patients that we’ve got running,” Kavanagh says. “Their chances of dying from another heart attack are between seven and eleven times greater than their opposite numbers of the same age who haven’t had a heart attack. But our recurrence rate is low. And it’s low whatever they’re doing when they have their second attacks — whether it’s sleeping or having sex or driving or whatever. It’s interesting that of the 58 recurrences, only 11 were connected with physical activity, while exactly the same number occurred in bed. Only one was associated with jogging, in that it happened around the time of jogging.” The figures are impressive, and they are taken further by another well known cardiologist of the “exercise school,” Dr Kenneth Cooper, of Houston, Texas. “The great interest in exercise started in the mid to late 19605,” Cooper says, “and by 1978 it was estimated that there were as many as 25 million regular joggers in the USA. Critics anticipated that this jogging boom might bring a significant increase in sudden deaths. However, every year of the last decade there has been a decrease in heart attack deaths, and in fact the 1978 figv » for heart deaths is expected to be 28 per cent down on the 1968 figure.”

Other views are more extreme. American doctors Thomas Bassler and Jack Scaff claim that established marathon runners have “permanent immunity” from heart attacks. The case of Dennis Stephenson seems to contradict that, yet Norman Sharpe does suggest that the runner may have received some protection from his hard exercise. “If he hadn’t been a runner, and having a tendency to high blood pressure, he may have got into trouble sooner. Which I can’t prove, obviously. That’s just my personal feeling.”

Mrs Burrows, too, is convinced that jogging and squash prolonged her

husband’s life. “He had said that at the rate he was going he wouldn't reach 40 — and I’m convinced he wouldn’t have. That’s why he took up serious exercise again. I’m sure that exercise extended his life, as well as giving him pleasure.” An indication that intensive physial effort is not a crucial trigger for heart attacks comes from an analysis of 100 deaths in Newcastle upon Tyne which were considered unusually sudden and unexpected. It was found that acute psychological stress and moderate' physical activity were more signific a n t than very strenuous exercise. But Peter Burrows. Dennis Stephenson and other joggers — including a 15-year-old boy with no sign of heart trouble — have died. So where does this leave the middle-aged man of sedentary habits who is trying to decide whether jogging will make him healthier or kill him? “The problem,” says Dr Dan Tunstall-Pedoe, a cardiologist at St Bartholomew’s Hospital in London, “is that although exercise benefits the vast majority of people it is a risky past time for a minority. Can you predict these minority people? The answer is no. You can say in statistical terms which sort of people are most likely. And you can say that those people who seem to be at high risk should take certain precautions, like checking with their doctors or getting thorough screenings. But it isn't easy. Roy Shephard goes so far as to lay odds on the risks: “In the case of reasonably healthy middleaged athletes who engage in sustained periods of vigorous exercise, like rugby or hiking, I think that during the period of this activity their risk of cardiac death is increased by a figure of three or four, relative to what it would have been if they’d sat at home reading.” Such a risk level, Shephard adds, is almost imperceptible. He points out that several studies quantify the long-term benefits of exercise. “On that basis, if your statistical risk goes up by three or four while you go out for 20 minutes, it’s only got to drop to about ninetenths of the other fel-

low's to put you ahead for the rest of the day. Depending on which studies you give greatest credence to. your risk for the rest of the day could be as low as 0.5 that of the fellow who has remained sedentary.”

So should you jog? Shephard: “There is a small risk, but if jogging is done in a reasonable fashion, carefully and gradually, I think you’re going to' be better off, in say, a year's time than if you hadn’t done it.” Tunstall-Pedoe: “Everyone exercises every time they walk down the road. It’s all a matter of degree and relative risk. People who are sedentary and overweight are a’ little more at risk, so they should take a little more care.”

And Norman Sharpe sums up: “What comes out of Dennis Stephenson’s case is the importance for runners, like everyone else, of having a medical check somewhere along the line, and to take a note of funny symptoms. A changed lifestyle is the obvious way to try to correct many of these problems and, perhaps paradoxically, there's no better way to alter one’s lifestyle in western countries than to go running. “Its perhaps not so much the running that’s beneficial but everything that goes with it. The fact of the matter is that hundreds of thousands of middle-aged men have coronary artery disease and are running with it, and it’s a good thing they are."