I realize this post is a little late (as it is beginning of February) but it seems like the flu is still going around so I figured- better late than never!
When you train when you're healthy (cardio or weight lift), it's pretty rough on your body. Inadvertently, your immune system becomes compromised. This stress is what, in time, makes us stronger.
So what happens when you're sick?
I personally think you should stay home for anything more than a head cold. Put yourself in other people's shoes- would you want to be working out next time to someone who is sneezing, coughing, blowing their nose, etc right next to you? Any flu symptoms- stay home. No questions. If you are sick, your immune system is already compromised and fighting something off. When you workout- you are further compromising your immune system. If you do too much too soon, you could prolong your illness and symptoms.
If you have a home gym- you might be able to get away with cardio if you simply have a head cold. Me personally- I just want to lay in bed and recover as fast as possible. Your workouts are usually garbage anyways if you aren't feeling well- so why not recover quickly and get back to being 100%? Your progress won't go anywhere in a week. I PROMISE!!!
