Recently, about 27,000 runners began the annual 26-mile, 385-yard (42.195 kilometers) mass run from.
But if past marathons in Boston and elsewhere are any indication, perhaps up to 40% of these optimistic and determined souls will slam into a sudden sensation of overwhelming, can’t-do-this fatigue several miles (typically about five) before they get a chance to experience the glory of crossing the finish line.
It’s called “hitting the wall.”
Getting through, around, or over hitting the wall is part of the mystique of marathon running, although there’s a physiological explanation that’s not all that mysterious: when runners hit the wall, their bodies have run out of the carbohydrates needed to sustain intense physical activities like long-distance running.
Benjamin I. Rapoport believes many runners could avoid hitting the wall if they put a few key facts about themselves and their target marathon time into the online calculator he created, which can be found at (more…). The calculator will tell them how many extra calories they should get from pasta, rice, or other high-carbohydrate food or drink before (and in some cases, during) running a marathon.
*This blog post was originally published at*