Both are raising money for Macmillan Cancer Support and have exceeded their initial £500 target by 264%, but are still welcoming donations as they look to hit £2,000 worth of donations.
Detailed on their Just Giving page, the duo said: "We are filled with excitement, nerves, fear and apprehension but most of all pride. For something so significant, we felt that we wanted to make it special not just for us, but for many.
"Thinking positive is only the start, to cross the line we know we still have a battle ahead. But we are determined, we are strong and we will do it. We ask that you support us by giving to our nominated charity. If we all do our bit, we all do what we can, we can make a difference.
"Thank you to everyone who has made this happen for us - dig deep in your pockets please, your kind gesture will be with us as we cross the finish line!"
You can donate to the cause by visiting https://www.justgiving.com/crowdfunding/ShaniandRach
Good luck to all participants of the London Marathon this Sunday, especially Iron supporters taking part!
