A man warming up on a treadmill for a group fitness class said he felt lucky to be alive after a car crashed through the wall of his Los Angeles gym, knocking him off the machine.

Samuel Kiwasz was at Anytime Fitness in Culver City on March 29 2019 when a red SUV came careening through the wall and ploughed straight into his treadmill.

"It's a miracle that I'm alive," Kiwasz told local media.

"All of a sudden there was this loud crash and the glass came flying and I got hit ... and I got shoved back and I went flying and rolled to the side so I wouldn't get crushed."

The driver allegedly attempted to leave the scene but was stopped by an off-duty police officer.

She later told police that her brakes failed, according to local media.

Nothing could have prepared me for this. A man is on the treadmill at a fitness center in Culver City, CA. He is about to put his headphones in and work out. All of a sudden, a red car runs through the wall and into the treadmills. I hope the guy was ok!