When it comes to the hills, though, a lack of conditioning can mean that the discomfort overwhelms the enjoyment altogether. As I know from experience, going unfit to the hills and struggling rather than enjoying is dispiriting. And that's just on a day trip, never mind day after day consecutively, with a heavy pack. I'm not unfit at the moment, but am I fit enough? Do I have that margin of safety? The thought of complete exhaustion, in bad weather, somewhere between Loch Tilt and Gaick, is not a pleasant one.
With this on my mind, much of the past few days has been spent leafing through the introductions of various accounts of marathon treks in the Highlands, trying to glean not just what these guys did about planning and logistics, but what kind of physical shape they were in before they started. Did they do any training?
Martin Moran (The Munros In Winter) and Mike Cawthorne (Hell Of A Journey), who made winter conquests of all the Munros and all the 1,000 metre peaks in Scotland respectively, talk about the importance of training and fitness. Moran details some of his routine, which involves a lot of running up wooded cloughs in Derbyshire. His fitness is clearly immense. He puts in some days that would be considered huge in any season, let alone winter: for example a full round of Glen Lochay. Obviously the physical demands of coping with freezing temperatures, wind chill, deep snow and fleeting daylight, mean that to maintain that margin of safety, fitness has to be taken deadly seriously. Scottish mountains in winter don't just look different, they are different.
Dave Hewitt and Hamish Brown, whose exploits took place in summer, are coy on the subject. Hewitt describes himself as possessing 'reasonable fitness'. Brown, in the introduction to Hamish's Groats End Walk, claims never to train for his long treks. That's about it.
What they doubtlessly had, though, was the benefit of living close to the Highlands and being able to visit frequently, perhaps every week, consistently building up fitness, endurance and experience. They got fit for the hills by climbing hills. My hillwalking - a day or two every couple of months at the most - can't really be counted as part of any fitness regime. I need to be doing other things. Sticking with the weights, certainly, but I also need to get my body accustomed to what it will actually be doing: walking long distances with a heavy pack. And in the absence of actual hills to practice on, what better way to enjoy a stifling London summer than tramping the streets with a backpack full of iron plates.