Originally Posted by Tchiowa

Your shoes are too small. You should have about 1/4" gap between your toe tips and the boots. Also, make sure the rest of the shoe is tight. If your feet are slipping forward then you're going to be hammering your toes on the shoe. And keep your toenails really, really short.

Try this, no guarantees. I wear the japanese "toe socks". Injinji is the brand I use. I wear a smaller size than I should so that the sock is really tight on the toes. Then I wear a second pair of socks over that. Plenty of padding, proper fit shoes, I haven't had runners toe or even a blister in years.

One other thing, if you've got a lot of pain while the nail is black (you usually do) there's a way to alleviate that. The black is from blood trapped under the nail and the pain is from the pressure of that. Disinfect a needle and slip it under the toe nail into the blood. Don't worry, it's not going to hurt. The nail is already separated from the toe at that point. Drain the blood, slather it with disinfectant and let it sit a few hours and you're ready to go.