Local competitors in an inaugural London Grand Prix cycling event this weekend say they are looking forward to the challenge.
The London-Surrey 100 begins in the Queen Elizabeth Olympic Park and finishes on the Mall, having followed much of the same route as the London 2012 Olympics road race cycling event.
Thousands of people are due to take part in the 100-mile race.
Among them is Malcolm Vincent, from Ringstead near Thrapston, who is raising money for Action Medical Research for Children, after his twin daughters were born prematurely last year.
“I am looking forward to it,” said the 48-year-old. “I have been cycling to and from work (in St Neots) two or three times a week, which is a 40-mile round trip and I have done a ride of 90 miles. I am feeling good.
“They have got a sweepstake at work on how long it will take me. I am hoping for somewhere between six and a half and seven hours.”
Mr Vincent also hopes to spend some time riding alongside Olympic gold medallist Joanna Rowsell, who is an ambassador for the charity.
Meanwhile, two GPs from the north of the county will also be taking part.
Clive Shackleton, 54, from the Eskdaill Medical Centre in Kettering, and 50-year-old Michiel Vaal, from the Corby Diagnostic Centre, are raising money for Help for Heroes.
Dr Shackleton said: “We’ve been training hard, but 100 plus miles non-stop will always be a tough task.”