I have to agree with Sofa on this one. I've tried more than once hitting arms after either back or chest, and each time I got absolutely nothing out of it. But when I do them on their own day, focusing on heavy free weight exercises, close grip bench, weighted dips, standing barbell curls, thats when my arms grow. Different strokes for different folks, but if you say the pics I just posted you can see that its worked for my arms