My wife and I did the caressing the sea tour with Aito and it was absolutely epic. We're not avid…read morecyclists but are in decent shape but nonetheless we rented e-mountain bikes because the Basque Country is so hilly / mountainous. We rode for 6 hours including stops and that took us 80 km and a total climbed elevation of 4,200 feet. Aito was an awesome guide as he's insanely familiar with the area, super friendly, a great teacher and quickly adjusts to your pace. Would highly recommend to anyone from advanced beginner cyclists to avid cyclists. There was another group going out for a much more intense ride than ours on regular road bikes.