Outdoor sports. Any of the following can consume your whole time, and have huge communities of full-time devotees: * Rock Climbing * Mountaineering

Outdoor sports. Any of the following can consume your whole time, and have huge communities of full-time devotees: * Rock Climbing * Mountaineering * Kayaking * Paragliding * Kite/Windsurfing * Surfing * Snowboarding (if you ski, skiing if you snowboard) * Backcountry skiing (aka ski-tour)