I'll play the age card and say "not as tough as I used to be", however if you want to gauge how tough you are, here is a good way to find out. Check out the United States Adventure Racing Association to find out about a sport that is continuing to grow in popularity.
If you and your team want to 1) get in shape, 2) practice working as a team under stressful conditions, and 3) practice a whole bunch of useful survival skills, this may be the race for you. Most races run anywhere from 6 to 30+ hours and include travel by bike, kayak, and trail running with a heavy emphasis on navigation and orienteering (the old fashioned way with a map and compass as GPS devices are not allowed). Races test your endurance in the cold of winter and in the heat of a summer and take place everywhere from swamps to deserts to mountains to prairies. Races also have interesting names as 'Howl at the Moon' adventure race to 'Amphibious Warrior' adventure race. This is definitely something I will be taking a closer look at.