I just have to deal with it [injuries] if and when problems happen. It's obviously a concern and I've been very careful with my training, making sure I warm up and warm down before everything and not pushing myself too stupidly.

I've always been a decent runner so I've never been massively unfit, but for this I've got stronger. I've got rid of a bit of podge and I'm just a bit leaner, which means that I'm just quicker at moving, I'm more agile and I recover much better as well. At the moment I feel ultra-fit and it's been an amazing change.

What's most troubling is the open water swim. It's windy, the waves are getting in your face and the water is a bit dirty. And there's silly things like you can't touch the bottom if you swallow a mouthful of water.

You wouldn't run a marathon the day before you run a marathon, you need to leave some sort of surprise for your body.

At the end of October I started doing a bit more swimming and learning how to swim properly, because I hadn't really done it since I was at school. Then I really accelerated in December and for the whole of January's I've been doing at least one thing a day - normally a swim and a cycle, or a swim and a run, every single day.

I just have to deal with it [injuries] if and when problems happen. It's obviously a concern and I've been very careful with my training, making sure I warm up and warm down before everything and not pushing myself too stupidly.

There's going to be a lot of eating. My listeners have tweeted me and said "You've just got to keep eating, keep your energy up and have someone on duty to give you a massage if you need it." It will be a case of getting it done and making sure I don't get too cold, because that's crucial for the muscles. So that's all going to be taken care of. But really there's not much you can do - if you start cramping up you've just got to get on with it.