Oh B that stinks! Ugh! I hate it when that happens and it makes me unmotivated to work out. You get all excited to do a class and boom - change of plans. Well on days when I want to take it easy I don't do yoga just because the last time I took a yoga class I was the object of ridicule. Seriously sis, you know how uncoordinated I am and for some reason balancing on one leg for a long period of time isn't me. It was my first class and every move the instructor would come by and correct me or I couldn't last long in a pose and fall over. So embarrassing! I envy all those that have balance. Also I kept thinking....is it true that people fart in yoga class and no one acknowledges it or laughs? For me that would be the hardest thing not to do is laugh. So throughout the whole class I was listening very carefully for a fart. Maybe that was why I was falling over? Who knows but now you have my background on why I don't do yoga.
Anyway I'm straying from topic....on days that I do a low key workout I usually do a really good stretch in the beginning and I'm talking about stretching each muscle for a good 2 minutes each. This should take a least 15-30 minutes depending on how tight you are. Then I would do a nice brisk walk on the treadmill for 30-45 minutes. There is a great walking workout on a blog that I read called http://carrotsncake.com/ She has some really great treadmill workouts that I do sometimes which make the workout not boring because you know how boring the treadmill can be. I mean you can only people watch for so long. If you are not a treadmill type then yeah the eliptical can be a great cardio if you want to get a little sweaty but not feel like you are going to pass out when you are done. If you are looking for a really light workout that is what I would do instead of yoga. Also stretch again after your cardio just so you feel loose and relaxed after especially if you did a hard workout previously. Hope that helps...that is my sisterly advice.