My first event was in Nottingham, aged 11, and the prize was a bike. I thought, 'Wow.' I had no idea what to wear. I think I did it in swimming trunks, then just put on a T-shirt and shoes for the bike part. Triathlons felt exotic. There was a technical and tactical aspect to it as well as the endurance challenge. I was hooked.
I was bribed into starting swimming with the promise of sweets and by being told that you can win medals. My mum had given me a bag of medals which she had won when she was young, so the idea of winning medals was very exciting.
I did my first cross country race when I was about 10 and absolutely loved it. I wasn't particularly good, so I didn't just carry on because I was good, but it just really appealed to me.
I was lucky enough to go to a school which gave flexibility around education and sport. We had a 1-hour, 30-minute lunch break, and were able to train during this time.
The run's the business end of a triathlon: it's where you win or lose the race. I like to get out very hard, make other people hurt sometimes, and other times leave it to the last kilometre and really win the race there.
I did a term at Cambridge University studying medicine, so I could potentially have followed in Mum and Dad's footsteps and become a doctor.
I wanted to be an endurance athlete from a young age. I remember being in a careers class at school and saying I wanted to be a professional athlete and the teacher replying, 'You're not going to make it; it's not possible.'
I don't know whether endurance sports attract obsessional people, or training for endurance sports makes people obsessional... it's the chicken and the egg.
Triathletes can push themselves quite hard, and I have seen people collapse on a barrier or pass out on a bike.
I knew I wanted to be a professional triathlete, but I didn't know it was possible until I won the junior champs. My dad said I should give Cambridge a go to see if I could do both, but it was only ever a trial.
Triathlon is a sport where the legacy is obvious. Anyone can do it; there are loads you can do. It is a massive participation sport. You can do it as a challenge, for charity or whatever. I believe it will continue to grow, and I will look forward to that happening.
The great thing about running is that you can get away to your own thoughts and get in a little bubble.
The best thing about having your brother in the same sport as you means you can go out and train together every day, and we can push each other on. That's something many of our rivals don't have when training day in day out.
It's better to train for 4-5 hours a week than to do ten hours one week then nothing for two weeks. It helps your body adapt and also maintains your fitness.
My school career was absolutely crucial to me. As an endurance athlete, some of the most important years are maybe when you are 16, 17, and 18. For me, getting that right was very important, and my school allowed me to do that.
We are quite different: I'm relaxed, and I get ready for races really late, whereas Jonny is really organised and punctual. I like to lead from the front in the run, whereas Jonny might hold back. Maybe it's because I'm the older brother, but I don't think there is a mental block that stops Jonny doing the same. I just think I'm a bit more gung-ho.