HOUSTON -

As the high-intensity strength and conditioning workout CrossFit explodes in popularity, so do the emergency room visits.

The strenuous workout isn't for the faint of heart, and as devotees flock to thousands of CrossFit gyms across the country, the “no pain, no gain” mantra often ends in injuries, according to doctors.

"A lot of people don’t realize the pain that they’re feeling is not getting the gain that they want, but actually causing the injuries," said Dr. Kelly Larkin.

Larkin is the medical director of Emergency Services at CHI St. Luke’s Health Baylor St. Luke’s Medical Center. He said emergency doctors are seeing more injuries resulting from CrossFit.

"The more severe injuries we’re going to see in the emergency room are generally going to be involved with muscle pulls," Larkin said. "We have shoulder injuries, elbow injuries and knee injuries are very common. We see them coming through the emergency department."

Doctors also see lots of sprains, strains and worse.

"We do have injuries that permanently stop people from being able to work out," Larkin explained. "To the extreme, there have even been spinal cord injuries from training in CrossFit. It’s very unusual, but there can be those types of life-threatening injuries."

Larkin recommends consulting a doctor before beginning any type of work out to determine your level of fitness. Also, find a good program with a qualified trainer.

"If you have a concern or something doesn't feel quite right, you need to pull back on it," he said.

According to Larkin, too often people try to push through the pain, but if there’s swelling or persistent sharp pain in a specific area, they should seek medical attention.