Let's talk about this a little further......
Whenever muscle is being broken down, there is an immune response, also depending on how much you've broken ur self down, will depict the level of sickness one may encounter......
With this being said, CK creatinine kinase is spilling over into the bloodstream from the muscles because they've been broken down too much. What will happen is an immune response, also let's not say it's cause of overtraining or muscle breakdown, your immune system is tailored and it responds accordingly to ur level of breakdown and overload.
Here are some solutions, 5gms of glutamine in the morning and before bed and 5-10 grams of backs with 5gams of glutamine before and after workout..... Will work wonders for u