I did a solid workout last Thursday, but near the end l could feel a very small amount of pain in my calf, nothing to bad. On Saturday l did a hill workout and again no real pain, but l could still feel the small amount of soreness. I have been stretching the calf before every run as well. If l don't do the session, it will just be a double today. I have been doing a lot of hard sessions this past month. When do you know the right time to postpone a session a few days? The session is 5 x1k