(CNN) - Personal trainer Mark Fleming flashes an encouraging smile as he pushes a young man through the paces. It's a simple exercise, stepping over a hurdle. But for his client, there's nothing easy about it. Fleming understands. He knows a lot about life's hurdles. And like his client, he is on the autism spectrum.
"I think it is important to help others on the spectrum to achieve the life that they desire. And exercise is a great way to do that," Fleming tells CNN. "I have them do this exercise to get the brain working... Coming to a new place can be challenging to an individual with autism."
Spotting a disturbing trend
Fleming graduated from the University of Alabama with bachelor's and master's degrees in exercise science. While working as a Special Olympics volunteer, he learned of a disturbing fitness problem for many of the participants.
"There was nothing for people with autism to stay active [after the Special Olympics ended]. And they would end up regressing. A lot of the time, people with disabilities stay at home a lot and become sedentary."
Fleming wanted to fill that void. So he started an in-home personal training service for people with autism and related disorders. That was three years ago. This past month, he opened his own gym, Puzzle Piece Fitness.
The puzzle piece has long been a symbol of autism, reflecting the uniqueness of each person on the spectrum. Fleming embraces that variety.
"I have to cater to their individual needs... Just because I have autism doesn't mean I know everything they are going through. I'm very open with them about that."
Growing the business
A challenge Fleming has faced, like many new businesses -- getting people to buy in.
"Dealing with this population, marketing is different. Word of mouth is the main way."
Fleming is hoping his in-home personal training clients will come into his new gym, help spread the word and grow his business.
"It's just to try to provide individuals a way to stay active, no matter where they are in their life" Fleming tells CNN. "Just seeing individuals get healthy, it's awesome -- the healthier these individuals are, the more likely they are to live their best lives."