Glasgow-born, you now train in Nottingham. What’s wrong with Scottish water?
There’s Grandtully [Perthshire], with the poles [slalom gates] suspended above the river, but it’s not technically demanding enough for world-class slalom training. The majority of top events are held on white water – or rapids – poured down purpose-built cement channels and the National Water Sports Centre in Nottingham is the best such training facility in the UK.

How did you become a canoe slalom athlete?
The first time I got into a canoe was at the age of eight on Airthrey Loch in Stirling. It was on a council-run course during the summer holidays. The next year I took a more advanced course and then, when I was 11, I joined the local canoe slalom club, CR Cats. I was no childhood superstar. I won the Scottish Junior Championships at the age of 16 but it was only a year before the 2004 Olympics that I thought myself capable of winning an Olympic medal.

Do you ever get recognised in the street?
No. Even if someone does point me out as that bloke who won silver at the 2004 Olympics they say: “He can’t be, he’s too small!” (Campbell is 5ft 8in tall).

When are your GB Olympic trials?
Our trials take place over three races next month. The first two are in Holland, followed by a final race in Nottingham. All three results will count towards selection for the one available place. I am the highest-ranked British paddler in the world and I will be disappointed if I don’t get the qualifying spot for Beijing. But it won’t be easy and I’ll need to earn it.

Will you go for gold in Beijing wearing your Saltire helmet?
I’ll win gold if I perform to the best of my ability. I’m not allowed to wear my Saltire helmet at the Games. Mind you, I wasn’t allowed the last time either. But I did!

Describe a typical course and what’s the toughest part of canoe slalom?
It’s usually about 250 metres long with white water rapids. Competitors must paddle through anything between 18 and 25 gates. There’s a two-second time penalty if you hit a gate and 50 seconds if you miss one! Competitions are decided over two runs. You need skill, mental toughness and physical power. The toughest part is putting those together to perform well consistently. A lot of guys can do one good fast run but only a handful are fast in every run of every competition. I consider myself to be one of them.

How do you juggle work with keeping in shape?
I’m a full-time athlete, supported by what’s called the Olympic Podium Programme through UK Sport. I’ve also been on the Scottish Institute of Sport programme since 2003. I live off my Lottery funding of around £25,000 per year, with things like training camps paid for by the British Canoe Union. I train about 10-12 times per week, mostly in the canoe but also several times a week in the weights room. I’m lucky that my training is very varied and often fun as opposed to being miserably hard. I don’t run or cycle because that won’t help me canoe faster.

Ever get scared of paddling in the white water?
I don’t get scared anymore. Well, maybe a little apprehensive! But when I was younger, the thought of going into the white water really got my adrenaline going.

Is it true your favourite food and drink is chip butties and Irn-Bru?
Well, they are some of my favourites but I don’t have chip butties very often. Mind you, I do still drink Irn-Bru. I suppose it’s my Scottishness! Overall, I don’t follow a very strict diet, just try to keep it healthy.

I hear you like to design websites.
Yes, I’ve designed a few, including my own, www.campbellwalsh.com. I like the technical side of it. I did pretty geeky degrees (he has a first-class degree in mathematical physics and a postgraduate diploma in IT). When I’m at training camps, working on the web helps take my mind off paddling for a while.

Is it true you’d like to work for Nasa and be an astronaut?
I don’t think they’d have me but it would be pretty cool. If I hadn’t paddled I’d have probably gone down the academic career path. It would be good to be an astronaut. I’m just waiting for Richard Branson to bring down the price of space travel before I go!

Who are your role models?
I read a lot of sports biographies and admire anyone who has become the best in their sport. John McEnroe had a reputation for his temper on the tennis court but for several years he was also the world number one! I’ve also got a lot of admiration for American sprinter Michael Johnson, who broke the 200m world record by a huge margin at the 1996 Olympics.

What tips can you offer aspiring young paddlers?
Get on to the white water as often as possible. There really is no substitute for practicing paddling round the slalom poles as fast as you can.