Long-distance running: running for a long life?

Physical exercise has been said to be healthy for the heart even in patients with various forms of cardiac disease [1–5]. A recent study published online in the European Heart Journal suggested that already being fit during the transition from the teenage years into adulthood may protect against heart disease decades later [6]. Men who had lower aerobic fitness levels when they were examined before entering mandatory military service at age 18 were more likely to have a myocardial infarction during a median follow-up of 34 years. Genetics likely play a large part in the aerobic fitness of teens but it could also be that men who are in good shape in their teens have adopted the sort of lifestyle that will keep them healthy later in life [7, 8]. What about the effects of extreme exercise, such as long-distance running [9], in particular marathons [10], or even longer distances than that, on health and physical well-being? Running races longer than a marathon (42 km, 26.2 miles) have grown in popularity. In North America, 15,500 people finished such races in 1998 and more than 63,500 individuals in 2012, according to UltraRunning magazine. To that purpose , researchers from Stanford University School of Medicine and the University of California (USA) decided to investigate the health effects of extreme exercise. They assessed the physical health in a large population of ultramarathon runners to establish a baseline for the Ultrarunners Longitudinal Tracking (ULTRA) Study [11]. The results are based on an online survey of 1212 runners who had completed at least one race of at least 31 miles, of whom some had even performed 100-mile races. The findings were reported on Wednesday 8 January 2014 in the journal PLOS One [12]. The participants in the study were 18 to 81 years old, with an average of 42 years: mostly men (68 %) of Caucasian race. Their average running distance for the previous year was 3347 miles, being equal to an average of 64 miles a week. In general, the study found that most of these runners are very healthy people, but most also do get injured in their activity. Important specific findings of the study were: 1) the ultramarathon runners had fewer carcinomas (4.5 %), heart disease (0.7 %) and diabetes (0.7 %) than the overall population-reported diseases, 2) the most prevalent findings were allergies and hay fever (25 %) and exercise-induced asthma …