Even an ‘easy’ part of this 125-mile walking trail on the French island presents challenges for mind and body, but the rewards for persistence are infinite

I’m on the easiest bit of one of the easiest legs of the GR20 – the self-styled hardest trek in Europe – so naturally here I am alone, lost in a cloud, with hands so cold I am seriously considering peeing on them.

In the guidebook, this was billed as a shortish, flattish day, a mere 10.2 miles (16.5km) with 670 metres of ascent. I had it circled as one to enjoy. Perhaps if it were warm, I would have a dip in Lac de Ninu, douse the fires in my calves. But when hail came, adding spikes to a slapping wind, and thunder began beating a drum behind the blank grey horizon, I thought: “Better put more layers on than take off.” I struggle with the zips, but just about find enough digital strength without resorting to anything unsanitary.