'He used to be in a coma, I used to be a fat guy': Father and son's touching pact

A father and son have made the inspiring pact to work together, as one seeks to lose weight and the other to regain function in his legs.

US boy Reece Dalashmit suffered a traumatic brain injury when he was just four in a car accident.

Now 12, he needs to use a “stander” as part of his therapy.

Meanwhile, his father Rick decided he needed to lose weight after blowing out to nearly 100kg, and made a deal with Reece: any time the youngster worked on his therapy, his father would hit the treadmill.

Mr Dalashmit posted an image online detailing the pact last week.

"He used to be in a coma, I used to be a fat guy," Mr Dalashmit wrote in the caption.

"My son is recovering from a brain injury.

“We have a deal now. If he's standing, I'm running."

He said he had now lost more than 30kg in the year since the heartwarming pact was made.

The photo posted by Mr Dalashmit has been viewed more than 2.7 million times since it was uploaded last week.