Six weeks into our half-marathon training programme, with the Mumbai and Delhi marathons coming up soon, the news of the death of three runners during the Detroit Half Marathon made us stop and take notice. Two of them were only 26 and 36 years old. Is there cause to panic? We decided to get an expert opinion from a doctor, who's also a regular runner.
Here's what sports and exercise physician Dr Rajat Chauhan had to say: Sudden deaths during marathons are very rare. The fact that three people died during this one marathon is more a case of the odds stacking up together than an indicator of risk. In 2006, Dr Paul David Thompson, Director of Cardiology, Hartford Hospital, United States, an authority in running cardiology, said, "During exercise, there is a death rate among healthy men of about 1 in 15,000-18,000." Regular exercise, in fact, reduces the overall risk. There is a higher chance that one will die of a heart attack while watching television at home or be run over by a bus while crossing the road.
What went wrong?
But if that's true and runners are in fact healthy people who exercise regularly, then what caused these deaths? One of the commonest and most easily preventable causes of sudden collapse in marathoners is Hyponatremic Encephalopathy, which is caused by drinking too much water, too quickly. The over-hydration causes electrolyte imbalance leading to low blood sodium levels, which can be fatal. You can avoid this by drinking water in moderation and only when you are thirsty.
Sudden cardiac arrests in young athletes are rare and unpredictable. They are described as Sudden Death Syndrome (Hypertrophic Obstructive Cardiomyopathy or HOCM), a condition that affects five in 1,00,000 athletes, who may be predisposed to serious cardiac problems. Genetic coronary ailments that are undetected can also cause sudden cardiac deaths.
To screen or not?
So how do you know if you're at risk? It's hard to say. Unless you have a known condition like diabetes or contracted arteries, there's pretty much no way to tell if you have a latent condition that will be exacerbated under duress. Exercise stress tests have a controversial role in diagnosing who may die suddenly. Thompson said, "Exercise stress tests are not very good at predicting who's prone to myocardial infarction or sudden cardiac death."
In 2007, during the US Olympic marathon trials, 28-year-old Ryan Shay, a four-time national champion, collapsed after passing the 8-km mark. Top sports medicine doctors had cleared Shay for running that particular marathon and had only told him that he may need a pacemaker when he was older. As you can see, medical screening can only play a limited role.
However, if you have a known condition or are in the high-risk zone for cardiac conditions, you should opt for exercise testing before signing up for a rigorous workout. Talk to your doctor so he can tell you how far you can push yourself and, more importantly, how rapidly.
Reap marathon benefits
Now that we're done scaring you, here's the good part. The benefits of running far outweigh any risks it may have. Numerous studies have shown that physical activity helps in preventing or reducing risk of chronic diseases like cardio-vascular disorders, diabetes, dementia, osteoporosis and even depression.
The important thing to remember is that sedentary people who don't run regularly should not suddenly start exercising vigorously.
In the final cut, more than any screening, it is you who can listen to your body and decide what it needs. Injury and 'good' pain are par for course in any sport or physical activity. My advice to regular joggers and exercise enthusiasts is to enjoy what you love doing most. Just ensure that you gradually increase the intensity and duration of the exercise. If you're not sure, seek advice from a doctor who knows what your physical activity involves.
Meanwhile, there's no need to press the panic button and go running to get expensive medical tests just because you're breathless at the end of 21 km. It only proves that you're normal, not super human.
Note for runners
Take gradual steps
Follow the 10 % rule -- increase mileage and speed by 10%.
Increase one at a time -- either mileage or speed -- never both. Don't ignore pain
Running 20-30 minutes has more impact on health than running marathon distances
Don't run if you have these symptoms on the day of the marathon:
Feel feverish or nauseous
Symptoms of flu
Breathlessness at rest