In the UK, it is estimated that up to eight young people die suddenly every week due to inexplicable cardiac abnormalities.
Maynard's friend, Robert Lamplough, was 28 when he died suddenly on New Year's Day - the cause of his death has never been discovered.
In honour of his memory, Maynard and three other friends of Lamplough are to run the New York Marathon on Sunday (7 November).
Cooke has donated an England World Cup Rugby shirt, which will be put up for auction.
For more information go to www.justgiving.com/cry-newyork.
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