Despite rounding laps that seem to never end, thousands voluntarily put themselves through the Tulsa Tough.
For many people, it's for the love of cycling. For others, it's something else.
"I got conned into doing the 66,” said cyclist Renee Thomas.“
Rider Amy Upton added, "I just wanted to prove to myself that I could do it."
One of the things that make Tulsa Tough different from other major bicycle races is anyone, at any skill level and age can participate. The races are broken down by child races, men and women skill-based categories.
"I've been training with the Divas,” Upton Stated.
Upton is new to the sport and so is her friend Mia Higgins. Higgins' boyfriend took on the track last year.
Now, it's her turn.
"I got so excited watching Tulsa Tough, and I thought, ‘If he can do it I can do it too,’" said Higgins.
Thomas, Upton and Higgins represent just a few of the people participating.
Thousands of people from 36 states and six countries are competing, and the toughest will race it out for a grand prize of $100,000.
But, the bravest will take on Cry Baby Hill.
“We're going to do the double tough baby, the double tough,” said Thomas.
With a little pressure from her friends, Upton just may take on the hill too.
"I don't know. It’s pretty tough,” she said. “That’s a lot of climbing."
The final day of Tulsa Tough races starts back up Sunday morning at 8 a.m.