Fern Britton is expected to attend the popular Chilterns Cycle Challenge in aid of Rennie Grove Hospice in Aylesbury on Sunday.
Cyclists will gather in Kingsbury, Aylesbury, where the challenge starts and finishes.
Riders can choose one of three routes with distances of 75 miles, 35 miles or 10 kilometres.
The 75 mile riders will set off between 8-9am, the 35 mile riders between 9-10am, and the 10 kilometres riders will set off together at 11am.
Particpants will include cycling enthusiasts, children and beginners.
Hand cyclist Luke Delahunty from Stoke Mandeville, who works at the hospital, is tackling the 75 mile route.
A tandem will be ridden by Neil and Alison Gray.