By Justin Harper Published: 2:18PM GMT 15 Mar 2010  'I got £50,000 for 21 seconds' work' Photo: Getty Images  How do you think your childhood influenced your attitude towards money?  I had a very middle-class background so I was never poor or well-off. I got pocket money, which taught me the most important lesson: that you should never spend what you haven't got. Once I'd spent it, that was it, my parents said.  So have you ever been really hard-up?  Yes. I was on the dole in about 1989/1990. I had already started swimming at that stage but wasn't earning anything from the sport and was getting a bit fed up. So I signed on for a while before I started a series of jobs to earn some money. I was a courier driver, a groundsman, a lifeguard, a double-glazing salesman and worked in a council office. You name it – I did it. One thing I'm not afraid of is hard work.  It was during this time I realised I would have to work hard at something if I wanted to be successful so I went back to swimming.  I knew I was good at swimming as I'd been the fastest 11-year-old swimmer in world. The penny dropped that I would have to train very hard if I wanted to make a living as a swimmer and I needed to see it as a job.  This is when a lot of people give up as they fear they might not make it and won't have anything to fall back on. But so many things in life are a risk.  Are you a saver or a spender?  I'm a bit of both really. Going back to my childhood, I never spent what I hadn't got and that has stuck with me as an adult. My income is a bit erratic so I'm never consistently one thing or the other. I do television and radio work, modelling (Mark is the face of Wellman vitamins and Braun shavers) and other appearances so each month's salary is different. So in a good month I'll save half and spend half.  Do you invest in the stock market?  I took out a Pep which I cashed in to help pay for my old house but I don't really understand the stock market. I know you can make a lot of money from shares but it's just not for me as I'm not much of a gambler. Most of my money is sitting in a bank account earning squat.  And I don't have a pension either. I'm a good example of how not to plan for your retirement!  Although to be fair I'm more interested in property. I own an apartment in Miami Beach from when I used to train over there and am thinking of buying a couple of places over here. I think these will be my pension instead.  What's the most you've been paid for a day's work?  I was paid £5,000 to dance at a corporate gig which was a shock if anyone's seen me dance. I'm really good (he laughs). It's not what I do, but I'll do whatever comes along. I'm not really fussy. (Mark got knocked out on week six of 2008's Strictly Come Dancing which was eventually won by Tom Chambers).  Or you could argue that I was paid £50,000 for 21 seconds' work. This was the time it took me to break a world record and the bonuses I got from the sponsors and organisers of the meet for doing it. If you ask most athletes why they take up a sport it won't be for the money. If you're good at sport and want to earn money then football is for you. I was pretty good at football but preferred swimming.  But knowing you'll get paid if you perform well does help you get up in the morning.  And after a big win, have you made a really indulgent purchase?  Not really as that's not my style. But after I broke a world record I did go out and buy myself a nice sports car. It was a BMW M3 and cost about £25,000. My only other real extravagance is my dogs. I have two bulldogs called George and Ems.  Are you a big tipper?  I'd say I was fair. I'm definitely no Scrooge. When I'm in Miami I'll tip about 20pc because that's the going rate but here it's less. I appreciate restaurant staff earn some of their wages from tips but it should be down to their bosses to pay them more, as we're already helping out by eating there. And I haven't changed the way I tip just because I've been on television. You still have to deserve it.  Do you give money to charity?  I do a lot for charity but it mostly involves giving my time. I've made television appearances such as The Weakest Link and Celebrity Mastermind for charity and am involved heavily with an anaphylaxis (nut allergy) charity after a friend of mine died from it. I'm also involved with this year's Sport Relief but I can't give too much away as I don't want to spoil it. Some sports stars are doing some amazing things for this such as Lawrence Dallaglio who's cycling to all the six nations stadiums.  And of course I'm an ambassador for Surrey Sports Park (surreysportspark.co.uk ) which is all about getting people off their backsides and involved in sport at whatever level. It's in Guildford and it has some amazing facilities.  Swimming is not only good exercise, it can also save your life.  What advice would you give to young British Olympic hopefuls?  We have the Olympics coming up in 2012 and it's important we make the most of the home advantage. We have the support from the crowds and financially and we need to take advantage of this. The Lottery funding has played a big part in our success and we need to build on that.  You don't come into athletics for the money so it's important you perform at your best for yourself, your family and your country.  I didn't choose swimming for the money although I did OK out of it. I did it partly because my friends were all swimming. It's good to look at yourself in the mirror and know you did your best.
Mark Foster has just taken part in 'Let's Dance for Sport Relief', having shot    to fame in the BBC's 'Strictly Come Dancing'. He is Britain's most    successful swimmer, having broken eight world records and appeared in five    Olympic games.