Good for you dude. Several years ago I got into backpacking. But, at the end of a 3-5 day trip I was toast. So, I started going to gym so that the trips would be more enjoyable. Now, I'm in the gym 5-6 times a week. No 2 hour iron pumping sessions - just usually some lifting and cardio. Abs every time. And I run at a track a couple of times a week too. For me, there's no substitute for a few miles running, although I added heavy bag workouts a couple of years ago - outstanding cardio workout.