For me, it was basically a question of "what is the simplest thing that could possibly work?". I started with just taking a quick lunch and then going for a wal

For me, it was basically a question of "what is the simplest thing that could possibly work?". I started with just taking a quick lunch and then going for a walk, then I added some running around the block near where I live, and finally I added in some basic body-weight exercises (push-ups, sit-ups, etc).