Guy gets back on a bike to see how far it's possible to cycle during 24 hours of non-stop pedalling. With the help of bicycle brainiacs Miles Kingsbury and Mike Burrows, the man who designed Chris Boardman's gold medal-winning Lotus bike from the 1992 Barcelona Olympics, he builds a revolutionary tandem and pairs up with his friend, endurance expert Jason Miles, to see how far they can push their bodies at the Extreme Environments Laboratory at the University of Portsmouth. In the build-up to the final record attempt at the historic Goodwood Motor Circuit, Guy also learns about the science of cooking for athletes with the Head of Nutrition at Team Sky, Nigel Mitchell, who instructs Guy to lose five kilos of weight and recommends a new diet regime. Guy also works out the best ways of relieving himself on the move to save vital seconds. As the day approaches for the record attempt, news reaches the team that Hurricane Bertha is approaching.

• Guy Martin