Several mountain-bike routes in the Aulps Valley, especially for families: mini-guides are available, free of charge, in tourist offices. The Portes du Soleil has 650km of signposted MTB tracks, 24 mountain lifts open in the summer, leaving from the various resorts. These take out a lot of the effort of mountain-biking, giving you the time to admire the scenery and get your breath back!