Hi Scott,
Well, it's been almost 2 years since I had my AAA surgery and I am doing incredibly well, You will not enjoy those first few weeks post surgery and I had a couple setbacks (pericarditis, for one) but I toughed it out. Like everyone said, get out and walk as much and as often as possible... multiple times daily if you have the energy to do so. I used a step counter on my watch and tried to get above 10k daily... You will thank yourself later when you recover much quicker!! For sure, do those breathing exercises when you are not walking... I still use the spirometer to make sure I am still fit.

After almost 2 years, I am hiking here in the Rockies up to 12k+', snowshoeing, biking and still walking when not up in the mountains. There is lots of life left after your surgery and that made it all worthwhile for me.