Clare Balding introduces the opening day's action from the annual track cycling World Championships, held this year in Hong Kong.

Three gold medals are up for grabs in this session - the men's and women's team sprints and the women's scratch race, won in 2016 by Britain's most successful female Olympian, Laura Kenny. The absence at these championships of the pregnant Kenny, along with her husband Jason, means early British medal hopes rest with Olympic gold and silver medallist Callum Skinner in an otherwise inexperienced men's sprint team.

Sir Chris Hoy provides expert analysis, with commentary by Simon Brotherton and Chris Boardman. Show less