All received wisdom about acclimatisation suggests that you should spend a few days taking it easy at altitude before commencing on a trek. So when I arrived in Cusco in advance of trekking the Inca Trail, I had a few days to spare to explore locally. I had already planned a tour of the Sacred Valley, but decided it would be fun to see the Valley from its river; The Urubamba
This was a first for me, as I have never rafted before (unless you count a family rafting trip 30 odd years ago on some very tame rapids in Colorado.) I had opted for this as an acclimatisation exercise because I figured I would be sitting down and it wouldn't really count as exertion. As it turned out, there is more to rafting than meets the eye. You have a very long and involved safety briefing which instilled the fear of God into me, I was planning a gentle drift down a river and here I was being given instructions on capsizing. I needn't have worried, though. Once you get into a rhythm of paddling it is a lot of fun. The class 3 rapids were big enough to give me an adrenalin rush and fast enough that I forgot all about my impending trek and concentrated on paddling like crazy through the water. It was a fantastic way to let off steam. Buoyed by my success, I returned to Cuso elated. If I didn't make the Inca Trail, it wouldn't matter, I clearly had a future career as professional rafter.