Most people won't forget the moment they finished running their first 5k, but for Derek Mitchell, the moment was all the more special because of his circumstances.
He reached the point where he realised he had to do something about it. Mitchell weighs 570-pounds but used to weigh 625.
"I just knew that things had to change. If I was going to have any kind of hope for a future."
Mitchell started going out for walks in his neighbourhood. and logged it on social media.
Pretty soon, he started to have a great response about his quest for exercise. It inspired his friends to get healthy.
He says: "(They thought) if Derek was doing all this stuff, I'm going to do it.
"It's awesome that you can inspire people like that to get up and go for a walk too."
So what motivated him to go from walking to running a race? "If I can walk a 5k, anyone can. I'm living proof of that now," he says.
Towards the end of the race, Mitchell looked like he was flagging. Bystander Jim Moodie who was there to support a charity endeavour, spotted him struggling and said: "He was at that finish line but he just needed a little more help.
Moodie made a beeline for him and cheered him on. "I said 'Let's go, come on, we've got this'. His face lit up," says Moodie.
Mitchell finished the race but won't be resting on his laurels just yet - he has nine more planned.