10 gold medals don't come easy... First comes the graft. Thousands of hours on the pedals, forever turning left, following that black line round, pushing your body harder than it is designed to go. Then comes the sacrifice. All familiar pleasures stripped away in search of perfection. Then the pain. Muscles burning, stomach churning, an ache in the bones. To pull all of this together to achieve an Olympic gold is impressive; to be part of a couple doing this in the same sport is rare; to do it ten times between you is unprecedented. Laura Trott and Jason Kenny, Britain's most successful female and male Olympians, invite us into their world, on to the boards of the velodrome and down the back straight of British pro cycling to give us the inside track on what it takes to become a champion. This is the story of the races that gripped a nation; one of sprints and pursuits, tactics, mind games, medals and trials; of being so tired you collapse by the side of the track, so out of form you can't finish a practice session; of what goes through the mind of an Olympian as they power towards the finish line; and of how a boy from Bolton and a girl from Cheshunt became the best in the world, while finding in each other the perfect partner.