While the main topic of Saturday’s panel discussion at the Boston Public Library centered on barefoot running, the Boston Marathon was a frequent side subject.Christopher McDougall, whose experiences with the Tarahumara Indians of Mexico inspired his book “Born to Run: A Hidden Tribe, Superathletes and the Greatest Race the World Has Never Seen,” visited the BPL with a group of fellow experts on running, just a few days before the Marathon.”I had not (run) a step in years when I first heard of the Tarahumara,” McDougall said, admitting that he bought into the philosophy of “if you’re built like Shrek, you shouldn’t be running.” However, he said, “The marathon is the ultimate challenge ? they do four to 10 marathons at a time, deep into old age.”McDougall described the Tarahumara as learning to run at a young age – boys and girls between five to 15 years old play it as a game, chasing a wooden ball in a group over a half-mile course in which those at the end have a chance to take the lead briefly.”At every lap, those dragging behind are leading the pack,” McDougall said. “It won’t last long. But if they threw you in front of Ryan Hall (who set the US course record at the Marathon yesterday), you’d get a shock of energy. You’re no longer a Shrek-like shrub at the back, you’re Kara Goucher (who finished fifth in the women’s marathon Monday).”McDougall’s fellow panelists in the packed auditorium similarly touted the benefits of running as a group.”It’s great to yak and gossip,” said Harvard evolutionary biology professor Daniel Lieberman. “For millions of years, we were social carnivores who hunted in groups to kill animals. At the end (of a race today), a lot of us say, ‘My God, I want beef.'”Lieberman also delved into human history to offer a theory about the link between running and charity.”The Boston Marathon raises $15 million for charity,” he said. “In the old days, (humans) would run for food for everyone ? It was community, sharing, helping each other out.”The first modern marathon took place in 1896 at the Athens Olympic Games – one year before the first Boston Marathon. Ultramarathoner Scott Jurek, who holds the US record for longest distance run in 24 hours (a whopping 165 miles), had some advice for those running in the 115th Boston Marathon.”There’s not always an aid station around the corner,” he said. “At mile 20, try to break down the last six miles into small chunks – the next aid station, shady spot, the next foot forward. On the nutrition front, taking in carbs while running keeps the brain functioning and keeps the muscles firing.”Rich Tenorio writes a weekly running column for The Item. Email him at [email protected].