JACKSON, MO (KFVS) - CrossFit is one of the most extreme workouts on the market and is growing in popularity.
However, one physical therapist is raising questions about the effects of the program.
Researchers say they have found some people suffer from a condition that leads to kidney failure due to severe exertion from the CrossFit workouts.
Blake Guilliams,who owns CrossFit 573 in Jackson, said it's all about knowing your body and your limits. He said before any training takes place, he goes through the different techniques with the person.
He wants to make sure they know how and why the movement is important before they put the whole workout together.
Guilliams said they haven't had any medical issues since they opened and he attributes that to the education that takes place.
"One of our main phrases in here is check your ego out the door," Guilliams said. "That goes for trainers and students. If you are not feeling well, or hurting or not feeling at your best, let us know. We will instantly scale and modify or stop where you are at."
He said Rhabdo, the condition health experts are calling in question, is not unique to CrossFit.
Guilliams made it clear that CrossFit is not for everyone. They work with you through every step but he said he has recommended to some they look for another way to exercise.