I can't do vigorous exercise, because I have exercise-induced asthma. I used to be an avid tennis player, in great shape. But after 20 minutes of high cardio, I start to wheeze and that lasts for hours, even if I use an emergency inhaler or do a home treatment of inhaling albuterol from a nebulizer. So, if I do a lot of walking, that's easier for me because it never induces asthma attacks. So I am very limited in that way.