you could just open the window to get fresh air, and simulate, via treadmill, the hiking!
Simulations work for some, though. But they don't work for others, and this is what I wanted to hopefully make a bit more understandable.
I used to only go out to do grocery shopping, but then I started exercising by cycling, and now, when I don't get out near the woods for three days, I get a real crisis. After breathing in fresh air for 30 mins or so I feel much, much better.