I think you'd be surprised at our species knack for endurance. We may not run or walk fast, but we can run and walk for a long time. Google "endurance hunting." But yea, 26 miles in a day? That's actually not so rough. If you're doing 2 mph, that's 13 hours of walking. Throw in a few hours for breaks and steeps, so maybe 16 hours a day? It's not a cakewalk, but it's totally doable if you're in decent shape.