For runners, one of the most storied-and feared-stretches is Heartbreak Hill, 32km into the Boston Marathon. The 90-foot elevation gain over one-third of a mile would be a painful climb in any marathon, but here it's compounded because... " />

If the Boston Marathon is too easy for you, try these crazy runs

For runners, one of the most storied-and feared-stretches is Heartbreak Hill, 32km into the Boston Marathon. The 90-foot elevation gain over one-third of a mile would be a painful climb in any marathon, but here it’s compounded because…