Together with Gemma's friend, Laura, they successfully completed the Birmingham Marathon and they have now raised almost £1,000 for Tommy's, the baby charity.
It was Gemma's first marathon, and she ran it just 12 months after giving birth to baby Elsie - not to be outdone, George decided he'd run the entire 26.2 miles wearing a rucksack that weighed the same as Elsie's weight on race day!
George said: "For those who (like I used to) thought Birmingham is flat, it certainly isn't! Thank you so much to those who have already donated, it was such a boost during the race and makes all the aches and pains worthwhile.
"It was Gemma's first marathon, so she was entering uncharted territory and I was in awe of the way she kept on going. It's a huge distance to cover on foot, so a time of 6 hours 7 minutes is incredible just 12 months after giving birth. It was a very tough day, but the feeling crossing the finishing line is just indescribable."
Laura is an accomplished marathoner and she is on target for 18 marathons in 18 months!
Pic: George, Gemma and Laura after their marathon challenge