DOING INTENSE WORKOUT SESSIONS
For some reason people get the idea that when you get sick you work through it by doing more exercise than before. Maybe they think that general exercise is good for your health, so doing more while sick might work out?
Whatever the case is, it doesn’t end well. When you’re sick, your immune system is compromised and healing will take a long time. So in all likelihood you are putting yourself into a weaker state and increasing your risk of injury while sick.
That being said, what is smart to do is at least some exercising. The key here is volume. If you are sick, allow yourself to heal and you can do that by cutting back on the reps or sets that you do and gradually bring them back as you get better. The key here is to pay attention to what your body is saying and do your exercising accordingly.