Carl Sabah is a Belgian dentist who also happens to be one of the best ultramarathon

trail runners in the world.

But when Carl started running, he wasn't trying to break records.

In fact, he didn't even know that trail running was a sport.

For him, it was a hobby that he just stumbled upon.

I just always went into the forest and if it was a single track, I would enjoy it a lot

more than running on concrete.

So I'm not the type of runner who is very focused on heart rates and interval training and

track training and things like that.

I always go into a forest and then I let my mind wander and I let my legs wander and

for me, that's the perfect escape.

Now just six years since Carl started running in the woods, he holds the fastest known

time for running the Pacific Crest Trail.

He also holds the record for running the Appalachian Trail, beating his predecessor by four days,

pretty impressive for a full-time dentist.

I'm Shelby Stanger and this is wild ideas worth living.

Most champion level athletes train their whole lives to break records.

But Carl didn't even start running until he was 24 years old.

Don't get me wrong, he enjoyed playing soccer, but he was not a record-breaking athlete.

When Carl started working full-time as a dentist, he decided to look for an individual sport

that he could do anytime, anywhere.

When you started to become a dentist, I mean your student, I was studying in a fun town,

...