Any idea what it is????
It's a bruise on my bicep. We were doing a ton of heavy bicep curls last night and I think that may have been what caused it. Could be push-ups too, but I don't think so based on where it is on my arm. I got something like this once before on a different part of my arm. It doesn't hurt at all, and it didn't while working out either. I don't think it's any harm - kind of a war wound for working out hard.