Trail running in Vibrams is awesome. As it is trail running provides an uneven surface, which means every step will use a different combination of leg muscles.

Trail running in Vibrams is awesome. As it is trail running provides an uneven surface, which means every step will use a different combination of leg muscles. This prevents any one muscle from getting too tired, and balances out your leg. With Vibrams the effect is amplified even more; add in the fact that you're constantly aware of every step you take, rather than just plonking down your foot on whatever is there, and you end up with a form of running that can feel simply amazing.