I've heard it's bad for you, because your body obviously isn't 100%. I've also heard it's not a bad idea, because it will boost your heart/immune system etc. I'm sick. Started yesterday, and I'm not going to class today. Yesterday afternoon (I knew it was gonna hit me hard soon but wasn't full-on sick yet) I did 20 minutes on the eliptical (hard settings) and that's all. I'm obviously not gonna lift or anything, but is it a bad idea to go do a little cardio while sick? Should I just hang out for a few days then go when I'm 100%? What are your thoughts?