what always ends my workout streaks is my right shoulder. it always gets some odd pressure exerted on it and feels "pulled". my uncle who is some big orthopedic surgon suggests exercises that pull, not push to workout, but you really can't get a lot of lifting done with that. between every few sets of any exercise, i usually go to the cable machine and do some light workouts to keep my shoulder stretched and moving, it has wrked somewhat so far. anyone else have this problem?