If anyone had ever told me that one day I would read a book about fell-running, I would have thought that maybe a long journey with limited reading material would be involved. If anyone had told me that I'd enjoy reading about fell-running, I'd have started to worry. So imagine how strange it feels not only to have read a book about fell-running, but to have enjoyed it so much that I am now contemplating trying the sport for myself.

Don't you hate books that do this to you? I was perfectly happy not knowing about fell-running (which, by the way, is more mountaineering than cross- country running), perfectly content not putting myself through hell running up and down impossible slopes which are so tough, they send your body into revolt - heels a-popping, spitting up blood and pissing yourself, or worse. But now I am all sucked into an extraordinary world where very ordinary men and women scamper across mountains, push themselves to the limit, and enjoy it so much that they can't stop doing it.

This, more or less, is what happened to Richard Askwith. A reasonably fit man in his early thirties, he was lured into fell- running by his friend Gawain. Gawain and another friend, Charlie, are preparing for the mother of all fell-running challenges, the "Bob Graham round", and invite Askwith to join them for just one part of it, a section 18 miles and 15 peaks long. (The whole BG round is 72 miles and 42 peaks.) After a hard day's running, climbing, stumbling and puking (that is to say, a typical fell run), Askwith experiences "the climactic ecstasy of settling down in an empty pub with a pint of bitter and a packet of crisps". He and Charlie "luxuriate in what is arguably the greatest of all the joys of fell-running: the fact that, every now and then, it is over".

Charlie initiates Askwith into a world of heroic men and women called Joss, Eddie, Peter and Carol who finish races bloodied and with broken bones. But mainly he tells him about Bob Graham, a man who, on his 42nd birthday (in 1932), decided to run across 42 peaks in 24 hours wearing nothing more than a pyjama top and plimsolls - a devilishly difficult feat to which fell runners aspire even today. By the end of the evening, Askwith has decided to follow Gawain and Charlie in attempting to "do a Bob Graham" (but without the outfit). You sense this is the thread that will lead you through the book, and it is. I actually got excited and thought, "Wonder if he does it?" - but naturally, I can't tell you.

Askwith arranges his narrative chronologically, taking us through a fell-running year month by month. He intersperses these chapters with mini-biographies of great fell runners, great races and runs that he himself tackles. At times, this structure is messy. Some sections are much better than others, and even though the "month" chapters are short - sometimes just a couple of pages - I often found myself having to look at the heading to see where I was. I felt this sense of disorientation quite often while reading Feet in the Clouds (which is, by the way, a great title), and often got hopelessly lost in the sea of names and statistics. I doubt you would if you were a fell runner - but, as Askwith points out, few people are, and that number is dwindling.

The sections that really shine are those when it is just us and the author, on a run. Some of Askwith's sentences are superbly evocative. His final attempt at the Bob Graham was my favourite. I felt as if I had done the training, too, with the 60lb backpacks. It was like reading the very best diary entry: after a while, you start to remember it as if it were your own memory, as if you had actually been there.

Although I never stopped asking myself "why?", I also felt humbled by this lovely little book. It is about something very primal: fell-running seems to be a sport that turns you inside out and shows you what you're made of. Perhaps I, too, could have such superhuman strength, if only I could be bothered to find it. The thought left me feeling uneasy, rather ordinary, and not a little wretched.

Annalisa Barbieri is a writer and broadcaster