When training two or more different muscle groups on the same day (Example: Arms and back on the same day), should I exhaust one muscle group first, then move on to the next, or is it OK to switch muscle groups through out the workout?
Generally speaking, NWinters is right. You want to hit the larger muscles first. After I do back, my arms are pretty toasted a lot of time anyway, so it doesn't take much to finish the job.