1 It may cause rashes in hypersensitive people.  Iodine contrast can also cause an allergic reaction. Itâs an X-ray radiocontrast agent used for intravenous injections. Contrast dyes containing iodine have been responsible for severe allergy reactions (including deaths) in a limited number of hypersensitive people.
Do not resume a rigorous workout, because of the risk of further injury to the sore muscles. Massage is another way to reduce soreness. Massaging the muscles and promoting proper muscle relaxation will help keep muscle contractions down to a minimum.
I don't remember exactly why muscles grow bigger after working out, but I believe it has something to do with little rips in the muscle and how the muscle heals. Muscles hurt after working out because of the build up of a chemical called lactic acid.