Has anyone tried Pilates as an exercise form? Would it be too intense? I tried Tai Chi but the class went on so long; I just got over-tired and couldn't keep up. Same with Yoga. And anything aerobic is out of the question! I love walking and take my dog out every day; but I wondered if Pilates would help my 'core strength' as promised....or be way too much with my illness! Has anyone tried it?