Jessie J

My attitude goes back to my childhood. I used to audition for theatrical roles, and you can't stand out in a room full of ambitious eight-year-old girls by acting the wallflower. I realised then that I couldn't do things half-heartedly.

The closer I get to retirement, the more I feel it will be a huge change, a shock, because athletics has been the core of my whole life. I know I'll miss the feeling of running fast, the adrenaline rush, and hearing the crowd cheering me on.