Ya probably should start stretching after. Wouldn't hurt.Make sure to keep stretching man, every day. You can use some resistance bands too to warm up. Stretching helps circulation and increase blood flow to the muscles so I believe it also helps stimulate the tissue growth after heavy resistance training breaks it down. but...maybe I'm just making shit up in my head
I tweaked my right lat trying to configure my monkey arms around to wash my back. This happened just yesterday. I just give up and ask for help. I must looked like one of Jerry's kids in their lol. It was like a pretzel of twisted arm mass

