i agree you can do a little light lifting without prolonging getting better TO MUCH. but whats the point? if you cant give it your all then your just wasting time anyway. beleive me it is completely pointless to go to the gym and it will keep you sick longer causing more of what you are trying to prevent in the first place. weather im sick or not i make every minute under that weight 100% effective. if i cant give it everything i have i dont even go. for proof take a look around at all the lazy yappers in the gym and how far their progress has gone then look at the guy who trains like a raging lunatic and see where he is at. stay in bed drink shit loads of water and kick the sickness completely, then charge up with food for a couple days before you hit the gym.
if you want your body to acheive your goals you have to listen to what your body is telling you. if it is sluggish, tired, sore, slow, weak, ect it is not ready to work. if your body is full, thick, strong, giving you that explosive fealing, full of energy, ect its ready to work.