A legless CrossFit trainer is teaching other disabled people how to push their bodies to the limit.

Twenty-six-year-old Zack Ruhl can impressively bench 420lb and do push-ups in his wheelchair.

Handstand in a wheelchair? The answer's yes from Zack

Handstand in a wheelchair? The answer’s yes from Zack

Last year he opened up his own CrossFit gym where he offers free classes to other amputees.

Zack, from Houston, Texas, says: ‘Anybody who has ever told me I couldn’t do something – I proved them wrong.

‘When I am at the gym working out that’s when life’s the best.

‘The one word you cannot use in my gym is “can’t”. That word is out of your vocabulary as soon as you come in here.’

Zack was born with brittle leg bones and missing his thigh bones so doctors amputated both over the course of his life.

But his mother, Cheryl Corbello, showed him early on in his life that he was no different from able-bodied people.

‘At just 7 months old I would never just give him his baby bottle, he’d have to crawl in his body cast to get it,’ says Cheryl.

‘He used to ask me to leave stuff down on the cabinets for him so he didn’t have to reach up and I told him, “No – I am not going to be here forever you have to learn to do things yourself.”

‘I told him he could be anything he wanted and I didn’t care when people told him no, we were going to find another way to tell him yes.’

Cheryl taught Zack that he could do anything he wanted

Cheryl taught Zack that he could do anything he wanted

Zack started playing sports and lifting weights in junior high school but his coaches were reluctant to let him play.

‘They didn’t want me to play because they thought I would get hurt. I am the most competitive guy I know and in high school they had a chart on the wall where they posted the highest bench press.

‘I couldn’t squat or deadlift but I could bench and I wanted to be number one.’

Zack decided to take his knowledge and strength into his own gym where he could teach other adaptive people how to work out.

Zack is an inspirational teacher

Zack is an inspirational teacher

‘I feel like I’m a pretty tough teacher. I just don’t like excuses at all. Helping other people with disabilities is by far the best accomplishment I can get.

‘The classes are free for adaptive athletes because I know how hard it is not knowing what to do and a lot of people in wheelchairs feel like there is no hope.

‘My message for amputees or any disability would be: don’t let anybody tell you you can’t do something.’