Hiking can be a great exercise and fun! I use to enjoy running trails, but not as much anymore.
Spike, I think the DHEA could be the issue you were feeling off. From what I can tell, it can stem from inactivity. I was given a similar report not too long ago. The was I understood it was it's kind of like a spiral, you don't feel up to working out, so you don't, DHEA goes down, you have less energy, which means you don't feel up to working out, DHEA goes down more, you have less energy......
Now I try to do something, even if it's just a walk. I was told it can lead to diabetes and gaining weight and I'm trying to move the opposite direction.
But, I'm not a doctor and I'm leery of a "take this pill and it'll all be better" approach to anything.