I am working out now with a guy that used to be a very competitive powerlifter, he is 46, drug free and strong as shit. We do a light day and heavy days with appropriate assistance work (M,T, off, Th, off Sat, off). He does not do any shoulder or traps work and light bi work, mainly cause he doesn't beleive in it, but he also had a shoulder injury a while ago. We workout in the evenings, and I do 16 minute sprint intervals in the mornings. If I were to, in the mornings one day a week, hit shoulders hard, or bi's, traps, (basically work on one muscle group in the morning on an on or off day) should I be concerned about overtraining? Say something like heavy bi work in the morning, then heavy chest and tri's in the evening. I know the pro's do this shit, but I ain't turning pro just yet. trap work in the morning and squats and back in the evening. Just thought I would ask.