What to do if ... you sign up for a marathon

Alistair Gurney, a 27-year-old accountant from London, ran the Bob Graham Round last year. The 74-mile route covers 42 peaks in the Lake District, and runners must complete it within 24 hours. It is widely noted as the most difficult long-distance race in the UK

"Once I'd decided to do the event I found the training regime easy to stick to. I went on the Runner's World website and entered details of the event I was doing and how much training I wanted to do, and it devised a programme for me. It is crucial to make a training schedule and write it down; if it isn't written, it isn't real. A schedule gives you targets. Even more important is recording your runs so you know you are improving as you train. If you have one slow run and feel demoralised, you can look at all the others you've done that week and see they are better than when you started.

"There were some days when I missed a run, if I'd got stuck at work late or couldn't drag myself out of bed in the morning, but generally I stuck to my programme. If you fall off the wagon and miss a few runs, just forget them. You won't be able to catch up, so just move on and do your best with the next run. Don't be tempted [to force in extra runs to make it up], because it will mean increasing the volume of training too fast, which is when you tend to get injured or ill. I got proper shoes from a running shop; the staff actually watch you run and understand your needs. I was lucky and didn't have any major injuries, but lots of my friends who run have been prevented from running by injury, so I was wary of it. And if you do get injured, rest only gets you so far; get someone to treat you who understands joints and movement – a physio or a chiropractor.

"I'm interested in sports physiology, so I researched the effects that training and the food you eat have on your body. How much you have to modify your diet really depends on what you eat now. If you train a lot, you will need to eat a lot. Losing excess weight does help, but not eating enough will make you tired and lethargic and stop you training. In the six weeks leading up to the race I had no social life, as if you are drinking you are never going to get up in the morning to run. I was running several evenings a week and had to reduce my calorie intake too; that would have been difficult to sustain that for a long time.

"I was doing the event with a friend, which helped to motivate me, as if I failed I wouldn't just be letting myself down, but him too. Running with people is good for competition if you are doing a fast run; the company can also be nice on a long run if you are training a lot – there is a limit to how much 'me time' anyone needs and conversation can take your mind off the developing pains. That said, I do like being able to daydream and have a proper chat with myself devoid of interruption, and for the same reason I run without music.

"I built my training up from about 15 miles a week to 60 miles a week. It is important with any training programme to start slow and build up volume and speed gradually. I'd spend most weekends in the Lake District or Peak District, running. It was nice to get out of London but onerous at times, and I felt like I was always tired. It was definitely worth it, though, and I'd recommend that other people try to push themselves and do an event they find challenging, too. Running long distances is fun, satisfying, stress relieving, and one of the only sports in which you will always improve at a rate proportional to the effort you make. I felt a great sense of achievement, and it has inspired me to do more difficult events; I'm thinking of doing a long cycle race in the summer now."