Usain Bolt and Simone Biles lead countdown to Tokyo 2020's Opening Ceremony

The Opening Ceremony is today! We have two of the biggest stars in the Olympic world to kickstart our countdown to the big show. We look back at Rio 2016 with four-time Olympic champion gymnast Simone Biles. And sprint legend Usain Bolt opens up about his career, advice for athletes on the way up, and who to look out for in the men's 100m.