Are you talking like test flu or worse? I've only gotten it once - take a few days off, not gonna kill you but maybe try to do lite cardio/walking to sweat some of it out and LOTS OF WATER. Maybe add some taurine and Emergen-C
I'd say don't train, rest up, keep the doses going and once you come out of it start busting ass again. Rest is what makes you well. Training will just stress the immune system.
about 3 years ago i was on a tren/sus cycle and i cut my gums chewing on something, well like 4 days later i was extremly sick with a 102.5 fever and i felt like i had a major hangover for those 3 days.. I never went to the docs because i figured i had a cold of some sort but then i realized it was a gum infection which actually worked itself out..
I rested and ate shitty food the 3 days just so i wouldnt lose too much weight, i was sick as a dog and i feel if i ended up going to the gym i would of been much worse off.. I should of went to the doctors but was lazy and took a ton of flu meds
I would say relax and eat a ton of food so you dont lose weight..