When I began running as more than a hobby five years ago. I discovered that I would need some quality footwear for my feet. After a little research, I happened upon the "barefoot" training using the Nike Free. I was a little skeptical at first, but after trying them, I was hooked. These shoes are so light that you won't believe that you're wearing anything. They come with two different insoles for your different levels of training. There's a thicker one to start with and then a thinner one as your feet get stronger. The Nike site sells them and they're a little pricey, but the level of customization is incredible. You can select the colors for every piece and even put your initials and logo on them. When I wear the Nike Frees, they are so light and I feel so much faster. The training aspect of these shoes is documented as my feet and legs definitely got stronger in a matter of months. They are designed to be worn without socks. About the only drawback with these shoes is that wearing them without socks makes them kinda stinky after a while. They can be washed, but it breaks them down somewhat in a relatively short time. I also wouldn't recommend them for any other sports because they're not designed to withstand the cutting or change of directions in sports such as football or basketball. Other than that, these are excellent running shoes that will definitely make a huge difference in your run time. I highly recommend them to serious runners who are interested in cutting time off their run and strengthening their legs and feet in the process.