Often times the increased need for oxygen during exercise will force your respiratory system, specifically the nasal passages to dilate to allow more oxygen in to the body when it is under stress. If your symptoms were simply a head cold that usually means that the infection or bug is all ready working it's way out of your system and training is fine provided you respect the fact that you're body may still be less than 100% after fighting off the bug. I'm far from a doctor but this has been my experience over 17 years of resistance training/bodybuilding. Best of luck and let us know how it turns out.
