We have worried about exercising too vigorously since the time of the Ancient Greeks. The messenger Pheidippides ran 150 miles in two days when the Persians invaded at Marathon in 490 BC. When he reached the finishing line he gasped, “We have won” – and died on the spot. In 1909 a group of eminent doctors wrote to The Times saying that, “school and cross-country races exceeding one mile in distance were wholly unsuitable for boys under the age of nineteen, as the continued strain involved is apt to cause permanent injury to the heart and other organs.” And when the 52 year old running guru Jim Fixx died of a heart attack in 1984 while out for his morning jog – well, that proved it. (except that he lived nine years longer than his dad). And yet, doctors still want you to work up a sweat five times a week! What’s going on? The short answer to the so-called ‘exercise paradox’ is that pushing yourself is slightly dangerous – while you’re doing it. While you’re exercising your risk of dying from a heart attack just about doubles. That’s still a small number if you’re young or female; a slightly larger number if you’re older or male. But, when you stop, the body’s metabolism and hormone levels change for the next two days in a profoundly healthy way. So you end up much better off. Sudden death during exercise happens, even in young people who reckon they’re healthy. Let’s not pretend it doesn’t exist. But it’s incredibly rare – one study on American nurses put the risk at one death for every 36 million hours of exercise. And almost all of those who collapse have something wrong with their hearts. This is why there has recently been such a lot of talk about screening young players as they do in Italy. Since 1982 it has been compulsory there for all kids taking part in sport to have a medical examination and an ECG, an electrical test on the heart. About 2% need further tests, and some of these are no doubt disappointed to be told to stop playing completely. But there has been a 90% fall in the number of sudden deaths during exercise in Italy and the pressure is building to introduce it here.
Here’s the trick. Don’t push yourself. Build it up slowly. Be careful when you get over 50. And listen to your body – stop if it hurts. It is important to be aware of what your body is telling you. One study found that almost half of all athletes who died during exercise had had symptoms, like chest pain, in the previous weeks. And you don’t have to push yourself to the limit to get huge health benefits. The chances of sudden cardiac death for a middle aged man like me during a 30 minute brisk walk is tiny, compared to my haring after a fit teenager during an all-ages shinty game. Despite all these warnings, exercise is great for your health. Researchers in Seattle looked at the 145 people who had died suddenly in one year in the city. Those who exercised vigorously were two thirds less likely to die than those who were couch potatoes. And doesn’t all that running knacker your knees? Well, no actually. A study in California followed middle aged runners for 20 years. At the end 32% of the non runners had knee arthritis and only 20% of the runners. But different sports do mean different risks. There were 14 injuries reported by 1000 runners in one study over a year, 64 by football players and 96 by rugby players. 1 in 600 horse riders are injured every year, particularly novice riders. Horse riding in Australia was found to be the third most dangerous sport after motor racing and power boating.
So, exercising is much better for you than not exercising. Some pastimes are safer than others. And if you’re a middle aged man like me – be sensible!