Now that you are ready for a physical challenge...

Here are some MULTI-ACTIVITY adventures in the States (that I copied of National Geo)

BEGINNER: The Central Coast Adventure Challenge
18 mile kayak, bike and fast race through backcountry between SFO and SoCal.
May 16-17 in San Luis Obispo, California
tccadventure.com

ADVANCED BEGINNER: Adventure Week
Orienting work-shops, 3 hour sprint competition, an Xterra triathlon, trail running, mountain biking
June 5-14, near Coeur d'Alene, Idaho
adventureweek2009.com

INTERMEDIATE: Adventure Xstream Summit
Part of 6 race series, the high altitude summit instalments plays out between 9000-12000 feet. Single track and Alpine lake terrain
25 July, Frisco, Colorado
gravityplay.com