Ellie Simmonds: The Paralympic swimmer reveals all about her sweet tooth, psychological challenges, and why she's afraid of lakes

I never thought of swimming as a career I just did it because it's a hobby. I learnt to swim at the age of four or five. My parents took me to a club where you go from learning to swim to competing. I got chosen to swim for the club and just really enjoyed it and did little leagues and galas on the weekends.

I'm naturally very competitive Both in sport and outside as well. When I was young, I did ballet, I did PE at school and I was in the rounders team. I was really keen on horse-riding, too, but I knew I had to give it up to give more time to swimming.

I train on Mondays, Wednesdays and Fridays It's just one session in the afternoon – and then Tuesdays and Thursdays is jogging. Training isn't just swimming up and down the lane; one session could be focusing on heart rates, another on lactic tolerance.

When I do have an aerobic session, I go into my own world Because that is about just swimming up and down, and I don't have to think about the lengths, I can think about what I'm going to do later or, I don't know, just anything. It's nice after a busy day to get in the pool and clear your head.

I'm just another student I'm studying psychology at Loughborough and there are so many sportspeople here – you actually see top athletes walking around – but people see them all the time, so there's no special treatment. I don't know if I want to do something involving psychology in the future, but it is enjoyable and I'm learning a lot from it.

When you're younger, you don't feel any pressure I didn't really feel pressure until probably [the 2008 Olympics in] Beijing and then after that at London [in 2012]. I felt quite a lot of pressure in London not only because of racing at home, but also because people expected me to get golds after the success I had four years earlier [where she won two gold medals, in the 100m and 400m freestyle at the age of 13].

Swimming outside the pool is scary I don't like not knowing what's underneath me – it's quite dark in lakes. I swam in the sea in Australia around the Great Barrier Reef, though, and that was incredible because you could see exactly what was underneath you.

Lining up for a race is more nerve-racking than putting a cake in front of Mary Berry [Simmonds competed in a charity series of The Great British Bake Off last year]. Baking is great, but I prefer having a finished product to eat. I most enjoy baking cupcakes – just cakes in general, actually. I'm definitely a sweet-tooth person. If I went to a restaurant, I would have a main and dessert rather than a starter and main.

I've always enjoyed reading I loved Jacqueline Wilson when I was younger, and Tracy Beaker. And when I was really young, I liked [Enid Blyton's] The Magic Faraway Tree. I always wanted to write my own magical book that involved baking. Ellie's Magical Bakery [Simmonds' first book, to be published in June] is about a girl who goes on an adventure and makes friends and bakes; the gist is that if you want to do something, you can achieve it.

I take every year as it comes First up, in August, I have the European Championships in Eindhoven, so that will be very exciting. The Rio Paralympics are only two years away, but I have to qualify first. I'm sure Rio will be good. We competed there in 2009 and it was great.

A four-time Paralympic champion, Ellie Simmonds, 19, is taking part in British Gas's SwimBritain campaign this year. Registration is now open for swims from 30 August to the end of September (swimbritain.co.uk)