The Boston Marathon is the world’s oldest marathons and one of its most famous.  Runners from around the world gather in Boston every April, along with 500,000 spectators, to enjoy this spectacular event.  The race starts in the suburbs and ends in the heart of Boston.  One of the more famous elements of this race is known as Heartbreak Hill, and if you ever talk to a marathoner, they will likely grimace at the memory of running this hill.  That may be surprising because the hill itself is only 91 feet long, which makes it one of the shortest hills in all five of the large city U.S. marathons. I always thought a 91 foot hill should be fairly easy for a marathoner who is in great shape.

But year after year, drama plays out at this site and many runners crumble. Why does this relatively short  hill cause such big problems for well conditioned athletes?  One reason is that the hill is actually quite steep, one of the steepest hills of all the US marathons.  In addition, it also comes at about 20 miles into the race, which is the point in a marathon when muscle glycogen stores are most likely to be depleted – often referred to by athletes as “hitting the wall."