Episode 2

Join some of Britain's biggest medal hopes on their journey towards the Olympic Games.

Cyclist Bradley Wiggins is back on the velodrome track, hunting a fourth Olympic gold medal, combining the pressures of fatherhood with the intense training necessary to be a champion.

And with little more than 500 days to go to the Games, there is a look at the rivalry for places building up within the Great Britain team, as well as the sacrifices being made by athletes desperate to compete at a home Olympics.