Often in the day or two after a sprint workout I notice small bruises in the shape of the letter “H” on the skin over my ribs. One on each side, always in the same place. Not a very deep dark bruise, but I can see the discoloration and a number of burst capillaries, and the area is mildly sore. Anyone else get this? Any ideas what causes it? Is it possible to bruise yourself by just breathing too hard?