First, the numbers: if you tackle the classic four-day Inca Trail you’ll have 24-26 miles to trek (depending on which trailhead you set out from), over 2,000 metres to haul yourself up and level yourself down, and over 3,000 steps to deal with in total.
In terms of fitness and technical challenge, this is considered to be a trek of moderate difficulty. The effort required, though, isn’t evenly distributed across the four days. Rather, the greatest lung-bursting effort is front-loaded into the first day and a half. The high point, Dead Woman’s Pass, is – at 4,198 metres – definitely the toughest of the three passes, both in terms of the potential effects of altitude and the sharpness of the elevation gain. There are, however, a number of campsites on the way to this first pass, and some groups opt to make the second day easier by staying at the highest campsite on the first night.