This is a day for your legs, not your lungs. Well over 550 metres up and almost as much back down again: your calves and knees both get their share. Nothing that knocks you out of your rhythm, but a day that keeps you busy the whole way.
After Fontecha you head out into open country, and before long the road starts to climb. You reach the highest point somewhere in the middle of the day. After that it’s mostly a matter of changing gears: a short climb, a short descent, and then again. It’s almost 7 hours of walking, breaks included. The last stretch takes you gently into the village of Villanueva de Valdegovía. Rucksack off, boots off, and nothing more to do for a while.