I XC skate quite often in winter. Wonderful excercise but very taxing on +50 body. Did a 20 km today with 1200 feet elevation, it really gets your system going. It is nice to give the upper part of the body a workout as well. There is so little snow now here in Oslo that I probably will ride my rigid steel Mtb
in the deserted remains of skitracks tomorrow. That is really fun.