Speed, focus, and adrenaline are just a few words used to describe one of the most extreme cycling challenges in the country and it's all happening in Green Country.

"It is a monster. You have to really, really want to do it," Frank Sohm said.

Sohm raced in the very first Tulsa Tough nearly 20 years ago. Now, he passes on his experience to help develop other riders.

"We have several riders out here and we've promoted a lot of the younger riders onto USA pro teams," Sohm said.

"I just finished the category 3 race," cyclist Dorian Jones said.

This is Jones's second Tulsa Tough. He finished in the top five Friday, and said these are moments to live for.

"It's so exciting to go into a corner at 30 miles an hour with a bunch of other guys. It's just so fun to go fast. That's my favorite part," Jones said.

If there's one race across the country that's worth being a part of as a participant or a fan, Jones said this is it.

"I can legitimately say this is one of the largest criteriums; one of the most exciting criteriums in the country and I don't have to go very far," Jones said. "I think this is hard to beat. I think this is probably the most exciting race you can come to in the country. If you want to experience criterium racing, you come here."

Races will continue bright and early at 7 a.m. on Saturday.