Eventing gold medallist and multiple Burghley and Badminton winner Mark Todd is to swap his riding boots for running shoes.
The 53-year-old New Zealander is to pound the streets of the Big Apple on 7 November in the New York Marathon.
Toddy and disabled former showjumper Catriona Williams will take part in the run to raise funds for Ms Williams CatWalk Trust — a charity searching for a cure for spinal cord injuries.
Ms Williams, who was confined to a wheelchair after a riding accident in 2002, will become one of the few people to attempt the marathon using a hand-cycle.
The charity’s website says Mark has been a supporter since 2005, recently becoming a patron.
He will be the flag bearer for the group of 20 Kiwis running for CatWalk. This is Toddy’s first marathon and he’s in “serious training”, the website continues.
Eventing World Champion Zara Phillips is also a CatWalk patron.
Mark has also been named as part of Equestrian New Zealand’s 11-strong performance squad for the London 2012 Olympic Games.