Just when I've been consistent with my weight training, the dreaded flu came for a visit...I hate to slow down on my weight training, not especially when I've been consistent and doing well at the gym. I certainly don't want to break progress by waiting too long between workouts. "This is friggin frustrating!"
So the big question is, do you workout when you're sick?
Personally, I still DO :-) but I reduce the load and intensity. However, this is only limited to when I'm down with flu. I DO NOT workout when I'm down with fever or have anything contagious (yes, I'm a responsible gym-goer).
For weight training, drop the weights and do high reps (20-25 reps, 3 sets) to sweat it out. If you don't feel like doing weights, do cardio instead. Remember to keep overall intensity low. The idea here is to sweat it out so that you feel better. When your body warms up and starts to sweat, your nasal passages automatically open up and you breathe a lot easier. But remember, only light workout and nothing intense as you just want to sweat it out.
Over do it when you are sick and you'll probably remain sick for a longer period of time. This is because your body will have to allocate nutrition in building muscles (as a result of the heavy and intense workout) as opposed to building and improving your immune system.
Think long term. Health and fitness is a marathon, not a sprint.