I'm fortunate in the aspect of backcountry fitness; my work provides me all the practice I need for the hunting season. During the winter/spring months, though, I try to maintain by lifting weights at least 3 times a week along with intermixed runs, swims, and bike rides. When it starts becoming a chore rather than fun, I take a break and hit the hills for some photography/shed/coyote hunting.. if there's one thing I have learned about maintaining a healthy attitude towards personal fitness.. it's that you have to enjoy your workouts, or you're bound to burn out. Finding something that YOU can stick to is the most important aspect..
I have to admit sometimes its nice to have someone tell you what to do and keep you motivated... either a personal fitness instructor, workout partner, or a workout DVD can help push you a little further than you would on your own. P90X and Insanity workouts are pretty fun on a poor weather day.