Yes, I started to go to the gym last April or so in order to train for my hike to Everest Basecamp. For 2-3 times a week I would basically do this:
1. Jump on a stationary bike, set to 20 minutes and manual level setting
2. Do 1 minute of a lower level and 1 minute of a harder level, and alternate
If I felt like I had mastered a set of levels (i.e. 10 for low, 14 for high setting), I would up it next time and do 10 and 15 for example. I would stay at these levels until I felt confident with them and then I would up them again. Right now I'm at 12 and 17, but it depends on the type of bike I find available at the gym. Usually it's the same one, but.. if it's a different one I just do it by eye.
Once I finished the hike and didn't die, I continued going to the gym and pretty much doing the above, although these days I do that 1-2 times a week. I try to do it twice a week, but life gets in the way.
When I was training for my Norway trip (specifically the 56k mountain bike ride I had planned) I did the same thing more or less, but I didn't have that alternating system in place - I just used presets on the bike like "mountains", "around the world", "random", etc.
As a result of all this my stamina is way better, I can for example do a jog and not get tired nearly as fast. My leg muscles are also much stronger than this time about 2 years ago. I find it really helped me in Nepal, and it just makes me feel better overall.
I've been meaning to do pullups/chinups at home, I have a pullupbar thing installed in my walk-in closet.. but I never get around to that. My upper body should get a workout, but it just never does.
Overall lately I've been shedding some weight and I feel great