Virginia, the amitriptyline can cause palpitations. (You probably knew that already.) I got them when I took the stuff for migraine prevention.
I spent a long time at the gym yesterday. 15 minutes on bike, weight machines and 30 minutes on the eliptical. Slept great last night. It's becoming a lot less difficult to get my lazy ass in there because I know how happy and full of energy I'll feel when I leave.