I had doubts whether I could even "get in shape" again. I mean I usually did a 20 minute jog every two days. Years ago I found every time I tried training faster, I'd get tired, slow down and stop my faster workouts. Several months ago I started training in a very gradual way and found out I can still do workouts of varying intensities if I do it in a gradual manner. Now I can walk up a hill without any fatigue. My speed and energy is also improved when I try crossing the street with my bike. Such a huge relief for someone who thought I wouldn't be able to do harder workouts ever again.