Toes!!!

I did my first 50 miler over the past weekend and I need some help! My toes look like someone dropped a hundred pound weight on them. I am not new to endurance sports and have had some bruising and lost nails in the past but this is really bad. I know to use Vaseline but maybe I did not use enough???

"Weight dropped on them..." is not too specific but it sounds as if you have a shoe-fit problem. Did you do a lot of downhill? That often butts the toes into the front of the toebox and gives you black nails. Sounds like you may need to look for a longer shoe that still grips the mid-foot so your foot doesn't roll around in the shoe too much. Of course, 50 miles is a long way!
Vaseline is generally thought of as a blister preventive. It doesn't work for me but some swear by it. Your problem doesn't sound like it has anything to do with lube or lack thereof. Injinji toe socks can work wonders if you're blistering between the toes.

Congrats on your first 50 miler! As ajj says, between mile 0 and 50 a lot can happen to our poor feet, but my guess would be the shoe size as well. I've always gotten my shoes a half-to-full size bigger than what the scale says. I've always used running shoes for long-distance hiking as well as running and I've never had lost toenails. Of course I can't logically rule out other factors, and for all I know, your shoe size is fine ... but for several running and hiking companions who have had blackened or lost toenails, the shoe size seemed to be the problem.