A patient of mine recently got a stress fracture after doing the Goofy marathon challenge. The Goofy is only trumped by the Dopey which includes  a 5K and 10 K run before the Goofy 1/2 and full marathon over 4 days!  As Clint Eastwood famously said in Dirty Harry, a man has got to know his limitations. I applaud the spirit behind these multi-day running events. They can prove to be disruptive as there is not adequate recovery time for many athletes. It is a similar principal with not allowing recovery when you are trying to build muscle.