COMPLETING just one marathon is a gruelling enough task for even the fittest of runners.

But Martin Dilworth is tackling the equivalent of almost four marathons in three days – and that is only the start of his challenge which starts tomorrow.

The 46-year-old, who runs the Dynamo Boxing Club, in Carlton Road, South Croydon, is planning to run 97 miles from the Tower of London to Dover.

he will then kayak 22 miles across the Channel before cycling the 220 miles from Calais to Paris.

Martin is being joined by his girlfriend Penny Ashby, 33, and friends David Sullivan, 45, Stace Fencott, 26, and Nigel Hodge, 35 to raise £10,000 for Help for Heroes, the injured servicemen's charity.

You can donate by visiting www.justgiving.com/londontoparisgrandprix