Attempted to run the Watchung 50K (here in NJ) yesterday in my Vibram 5-finger KSOs. Bad idea. The KSO soles are slick and 3.5 mm thick. Works great on roads and gravel trails. However, these trails were mostly rocks and covered in snow in the morning. But snow turned to ice and ice turned to mud as the race progressed. I was slipping from the beginning but the mud proved to be too much of a challenge for me. I ended up walking half the race just to get past the slick parts. The race was a 5 lap race. When my inner thigh muscles started cramping up from slipping during my 4th lap, I had to throw the towel in. So 40K is all I got after 6 1/2 hours of slippin' and slidin'. Also got real sore feet and a purple pinky toe from stubbing it earlier in the race. Have to find a good pair of minimal trail running shoes with stubby soles for next time. Also saw at least two runners eating baked potatoes. They both laughed at my arugula salad. I should try baked potatoes next time.