Ever since I announced in my previous column that I am training for a half marathon, friends keep asking me whether a full marathon is up next. My answer is always the same – no way. While running 21 kilometres seems a manageable challenge, running 42 just feels self-punitive. But all of this inquiring has me wondering whether there is an upside – or downside – to longer races.
Research in this area is scant, but a few studies do indicate declining returns, and even some evidence of harm. A of more than 55,100 adults found that, on average, runners had a 30 per cent lower risk of dying over the 29-year study period than non-runners. However, clocking up more miles a week didn’t accrue any extra benefit. While those who ran 32 km or more per week had a 23 per cent lower risk of dying than non-runners, those who ran fewer than 9.6 km per week had a 34 per cent lower risk.
During long runs, blood flow is redirected from organs to muscles, the small intestine and reducing kidney function as a result. The immune system also becomes suppressed for several hours after a marathon. But these changes are short-lived, if you give the body time to recover.
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Still, routinely running long distances raises the risk of certain long-term health problems, most notably cardiovascular ones. A 2020 found endurance athletes are especially prone to ventricular arrhythmia, a type of abnormal heartbeat, and that middle-aged male athletes have more calcium deposits in their hearts, which raises the risk of heart disease, compared with non-athletes. Male marathon runners had three times the number of calcium deposits than controls, and male athletes also have twice as many coronary artery plaques as non-athletes.
All of this suggests routinely running marathons takes a toll on the heart – at least for men. While fewer studies have been done in female athletes, research suggests they are less susceptible to the cardiovascular consequences of endurance running, maybe due to protective effects from oestrogen or lower testosterone levels.
This highlights an important caveat: many of these studies only looked at a small number of participants, many of whom were white male athletes. It is, therefore, challenging to generalise these findings to a wider population. Still, all of the research suggests that running a marathon doesn’t improve health any more than shorter races do.
I understand that, for many, completing a marathon is about more than getting into shape. And, despite the potential risks, many studies show that elite athletes live longer than the general population. So don’t let this article deter you. If you plan on running multiple marathons, just give your body enough time to recover, and don’t expect me to join you!
Grace Wade is a health reporter for ¿ìè¶ÌÊÓƵ based in the US
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