Any trades people here?

I was in pretty good physical condition before the bottom fell out in 2008, since then I've let myself totally deteriorate. Off of work 21 mos, 21 mos, 18 mos, 18 mos and just became so depressed nothing mattered. I'm wondering if anyone out there knows how to keep yourself in physical condition while off waiting on the "book"? How do you describe to a personal trainer the types of things we do so we can keep those muscles, stretched and strong? I quit smoking a year ago and this is my last dragon to slay. I enjoy being active but am so tired after work, climbing stairs, ladders all day I have no energy for anything after work. Advice??