So this is the second time I've gotten this bruise on my back in the last 2 1/2 months. It doesn't hurt at all and I've had zero trauma to my back to cause such a bruise. The only thing I can think of is that its got something to do with me exercising? Since mid November I've been going to the gym and exercising and I've lose 22lbs. Before that I haven't ever gotten this bruise. Anyone know anything about this type of bruise or a possible reason behind it?