It wasn't so long ago that trail running was considered to be something only nature geeks did in their spare time. I mean, who in their right mind would want to run up a mountain? Cue the sound of crickets chirping ...

Things have changed in recent years, however, and trail runners like 64-year-old Sayako Suzuki have found the challenge to be almost liberating.

"The trees, the wind, the earth and the feeling of freedom of running through the mountains is such a primal experience," Suzuki says. "I'm completely hooked."