It wasn’t that long ago Josh Gadsby said he’d never run a marathon again – yet becoming a dad to a child with a genetic condition changed all that.

“I think it has become far enough away in the rear mirror now,” Josh laughs.

He’s not sure how he will feel on Sunday when he runs the Sydney Marathon, but he is sure it will be worth it for the money he is raising for Children’s Medical Research Institute.

Josh ran his last marathon in Melbourne seven years ago where he declared he’d never run one again.

Three years ago, Josh became a dad to Charlie and his life changed. After noticing some delays, the family did genetic testing and found he had a rare condition. It impacts his speech and his intellectual development. Josh and wife Katie have been told it impacts 0.001% of the population.

“He is an awesome, happy, otherwise healthy child,” Josh said. “But this diagnosis is going to have a lifelong impact and he’s going to face a lot of challenges. He’s doing speech therapy, physiotherapy, and occupational therapy so we can give him the best chance in life.

“We’re very aware that if this happened 20 years ago, we wouldn’t know anything about it. We’re very grateful to have that knowledge so we know how to help him.”

Josh has run for charities before, but he knew that this time he wanted to run for research and when he learnt about the work being done at CMRI, he wanted to fundraise to help the 1 in 20 kids impacted by birth defects and genetic conditions.

“I started out wanting to raise $3000 and it’s amazing I’ve got to $10,000.”

Josh has promised his friends and family he’ll run the huge 42km race in under three hours.

“That’s the aim and I’ll be looking forward to seeing my wife and Charlie at the finish line.”

If you’d like to support Josh’s run, you can donate here: Josh Gadsby in 2025 TCS Sydney Marathon presented by ASICS