I was pretty much chronically sore this past week. The sorest I have ever been to be honest with you. My legs were sore for 7 days straight. My chest and back were abnormally sore for many days as well.
After doing some digging, I've concluded that the increased soreness was caused by creatine. I found this on Clarence Bass' website:
"After three weeks of either creatine or placebo supplementation, 40 male varsity athletes were interviewed and filled out a questionnaire detailing all side effects during the double blind study. Two side effects showed the greatest difference between the creatine and placebo group: sleep irregularity (creatine 47%, placebo 7%) and muscle soreness (creatine 53%, placebo 14%).
The researchers didn't attempt to explain how creatine might cause soreness, but my speculation is that muscle fibers packed with creatine may be more subject to damage as a result of heavy weight training. It also seems logical to assume that muscle soreness might cause restless sleep. Personally, I don't sleep as well when I'm sore after a hard training session.
The next question, of course, is whether the resulting soreness is harmful. I doubt that anyone knows the answer at this point. This does, however, strengthen my resolve not to train again until a few days after soreness subsides. Remember, Dr. Smith believes soreness "occurs to reduce activity during a critical time of healing."
I'm not stopping the creatine, but I'm glad I have a logical explanation as to why I've been so sore.