As Mumbai full marathon approaches, doctors have urged participants not to practice excessively as it may have adverse affects on the heart, especially for the adults and senior citizens, said doctors. “People doing regular exercise have a healthy life, but as overdosing of medicines is always toxic, similarly excessive endurance exercise like marathon running, has shown to have paradoxical, adverse effects on the heart,” said Ajay Pandey, Cardiologist at SRV Hospital. Pandey said heavy chronic exercising imposes certain adaptations on the heart due to excessive prolonged workload on the heart, like heart muscles hypertrophy, enlarged heart volumes, etc. Mumbai will hold a full marathon on Sunday. Thousands of participants are expected to participate. Cautioning of even sudden death due to excess practice, the doctors have also said that with recurrent strain on the heart, there can be adverse dilatation of the heart chambers along with patchy muscles scarring. “These changes are almost always asymptomatic, occurring over many years, but predispose to serious heart rate and rhythm irregularities, both atrial and ventricular arrhythmias, and can be a cause of sudden death in some people,” said Pandey. Experts said that though incidence of such cases are low – 1 in 40,000 athletes, unfortunately, there are no proven methods to screen for these potentially dangerous changes occurring with extreme exercising. Narayan Gadkar, Cardiologist at Mumbai’s Zen Multi-specialty Hospital, said that over training is not always in favour of the body, especially when it is the senior citizens and adults aged around 50. “There are many who have started vigorous running and practice for the marathon. Recent incident of a doctor who died while preparing himself for a marathon has brought the ill effects of inadequate training or over training to the front,” said Gadkar. “As one starts ageing, the body gets older and prone to heart diseases.”