Cardiac concerns

Is running bad for your heart? When done to excess, during periods of illness, then disturbing evidence says, quite possibly, ‘yes’

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Ever since Jim Fixx keeled over in 1984, runners have been worried that their sport might be bad for their health. Perhaps not worried enough, though.

Fixx famously helped trigger the running boom in America with his best-selling book The Complete Book of Running. Yet he was only 52 when he collapsed after a run and died from a heart attack.

Most people sought solace in the fact that Fixx had a family history of heart disease and had led an unhealthy lifestyle until his mid-30s. It will never happen to me, they told themselves.

I have been no different. So far I have breezed through my running life thinking that every run I do will strengthen my heart, not make it weaker.

With the heart being the main muscle and motor that drives the entire body, I’ve got a kick out of wearing a heart rate monitor during track sessions and driving my maximum rate up as high as possible. Then, I’ve looked in envy at world-class athletes who have resting rates of around 30 beats per minute and maximums in excess of 200 (a far more impressive ‘range’ than my own modest 50 and 180-odd).

What if we are all wrong, though? What if running hard, long distances actually damages the heart?

At this point I would say that I am not going miss my run today. Nor am I going to avoid going tomorrow, or the day after. The healthy benefits of running far outweigh any possible negatives. There is also no firm evidence that lots of running hurts your heart.

Saying that, research done by Athletics Weekly contributor Martin Duff suggests that there could be a problem. He has been in contact with dozens of athletes – including well-known figures like ex-British internationals Bill Adcocks and Bernie Ford – and has encountered too many ex-athletes with heart problems for it to be a mere coincidence. Given this, he is keen to spread the word so that some definitive scientific and statistically sound research can be undertaken into the subject.

Duff, a former 14:20 5000m runner, takes up the story…

Did our training lengthen our lives? Or is it now shortening them? I think the answer might be “both”. On the one hand, we have protected ourselves against artery blockage and subsequent heart attacks but, on the other, we may have caused other tissue damage.

From everything that runners have told me, it seems there are instances where atrial fibrillation (AF), which can put the patient more at risk of a stroke, has not been recognised by GPs. Some of you, like me, were initially diagnosed with exercise-induced asthma. I eventually “undiagnosed” myself and later the heart damage was recognised (firstly to a valve and then of AF). I was then moved from aspirin to warfarin and beta blockers. Running with the latter is like driving a car with the hand-brake on!

Some have not been so lucky and have had strokes. These could have been avoided if the probability of AF had been recognised and treatment made earlier. So, for those not on aspirin, warfarin or other anticoagulant drugs, please take note. The drug Pradaxa is also used, but I understand that it cannot be used where there is a leaky or damaged valve.

If a long-term trainer is exercising and suddenly finds a shortage of breath, it is unlikely to be a result of “old age”. It could be AF so my recommendation is to see your GP. If it is, treatment can be prescribed.

Current athletes training to high intensity will inevitably ask what they can do to avoid the problems? Years ago, Chris Brasher, the 1956 Olympic steeplechase champion and founder of the London Marathon, warned runners not to train through heavy colds, flu or viruses. At the time we largely dismissed the idea because we had to get our mileage in. Yet now it seems it may have been a sensible suggestion and that the high intensity training we all did 40 or so years ago, through colds and illnesses, may have damaged our hearts, leading to valve damage, irregular heartbeat and AF.

Dr Chris Pepper, Consultant in Cardiology and Cardiac Electrophysiology at Nuffield Leeds Hospital told one of Athletics Weekly’s readers: “It is well-recognised that long-distance competitive running increases the risk of atrial fibrillation. Some estimates put this at around twentyfold … I am sure there is much to be discovered about the reasons underlying the increased risk of AF in runners.”

My own cardiologist, Dr James Sneddon, agrees. However, the problem is, as my electrocardiologist, Dr Martin Lowe, explains, most GPs and even cardiologists typically see just one case of heart damage caused by high-cardiac concerns intensity training during their careers and therefore do not recognise the symptoms or the cause.

Canadian cardiologist Dr Larry Cresswell, who writes on, told me: “Endurance athletes have a much greater risk of atrial arrhythmias than non-athletes. These arrhythmias aren’t generally life-threatening, but they do cause grief and often require treatment.” The problem is that the symptoms have to be recognised and the appropriate medication given.

AF, if not treated with blood-thinning drugs like aspirin, warfarin or Pradaxa, can lead to a stroke and it is important that GPs recognise the symptoms and get the diagnosis right.

So what action should present-day high-intensity trainers take?

» Avoid running with flu or other viruses.

» Do not train while run-down or stressed.

» Get regular monitoring by qualified personnel for the onset of any atrial arrhythmias.

Dr Andreas Wolff has carried out research which shows that there is a link between high intensity training and heart damage. He looked at 300 top male Finnish orienteers and compared them with a larger sample of non-athletes. Both sets were approaching 50 years of age. He found that there was a 5.8 times more frequent development of AF in the athletes.

The above comments were part of a longer article that appeared in the December 8 issue of Athletics Weekly (see the back issues section of this website for a copy). Since then, the magazine has received a number of letters from runners and ex-runners who have suffered problems.

Duff is also still encouraging athletes to fill in a questionnaire which can be received by emailing him at the address:, but he also urges the medical world to take note and look into the area in more depth.

In conclusion, should you stop running? No way. Should you think twice about training hard with a cold or virus? Definitely.

Keep an eye on Athletics Weekly, too, because further news and developments are almost certain.

3 Responses to “Cardiac concerns”

  1. Ellie says:

    I thought that running, or other cardio excersise with a cold or virus was well known not be good for you. It has always seened obvious that pushing your body when its fighting an illness is never going to get you better quicker.

    • Martin Duff says:

      Yes Ellie, but we all had the milage bug. We had to do the miles per week we set ourselves. This is a common thread through the retrned questionaires.
      Martin Duff

  2. John Backley says:

    Martin, interested in your AF article. I was anathletic nut training twice a day occasionaly and busting a gut to do the 100mile a week. I was never a great runner(1.51 for 800 and 4.10 for a mile ) but I loved it.In my late 50<s (Im 72 now) I started getting dizzy spelsand cut a long story short finished up seeing a cardioligist from StTHomas hospital in London who diagnosed AF which I have had for nearly 6years. Very uncumfortable but still in this world Im on beta B. and Warf and going for further tests. I coach athletics now and fully agree with everything you have mentioned. Cheers thanks for your article (John Backley (fatherof Steve)

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