Amid high mileage weeks, I sometimes get a "dead" right leg (usually after I run). It is extremely painful to walk normally and I usually end up limping around the next day. It feels like my leg cannot support my body weight. If I suffer through a ten minute warm up jog the next day, it goes away on my run. Then, the next morning, it's back again. It does not seem to affect me after it gets warmed up, but I am wondering if I am doing damage by gutting out the workouts. I suspect it's a nerve thing or a Sciatica problem. I am three months out from Boston and, to this point, training has been going great. I avoid hills and faster workouts when it feels like that at the beginning of my run. Once or twice, though, it has prevented me from even getting started on an easy jog. Any ideas?