I'm not a natural runner. I'm friends with Ellie Goulding, and she'll be like, 'I've just done a 10K run' and I'm like: 'Why would you do that? How do you just do that?' But I will do that. I will do it.
'Just Do It' is exactly what you need to hear when you're in a moment of doubt. When you're struggling, especially with sport... just do it. Stop talking about it, stop complaining about the cellulite, or that you're not able to run fast enough for the bus... just do it.