In my Olympic history I don't think I have achieved my potential as an athlete. That's what I want when I look back at my career. I want to be able to say I gave it my best shot.

It's important that athletes can compete on a level playing field. And youngsters coming into the sport can know that if they are working hard and training hard, they'll see a true reflection of where they stand and what they can achieve worldwide and not be swayed by people who are cheating.

You can wish as hard as you like but all that really matters is the shape you're in on the day of the race. I've always felt these really big races aren't necessarily won by whoever is the fastest. They're won by the athlete who is the smartest and in the best shape on the day.

I just want to be in the best shape I can be. Not to stand on that start line and say: 'Oh my God, I have this injury and that injury.' I just want to be able to go out and race.

Plenty of people who are 38 have run really well in the marathon.

A half marathon is a good way to have a bit of fun and race against those girls and learn a bit more about them.The world half marathon is a world championship at the end of the day and it's important. I've win it twice and it's a quality event.

I've always been good at putting things behind me–I fall apart, do my crying bit, and then put it away and move on.