It's placebo, but use it to your advantage. As for your workouts, keep it at 4days max like Pinnacle said. During my last cycle i trained too hard, and about week 5 my joints started to hurt real bad and i couldnt continue, had to take almost a week off, and continue with less intense workouts, but by then it was too late, some off the pain remained for the rest of my cycle so i couldnt really give it my all, still got great gains nonetheless. That goes to show diet is more important then your training.
You need ot find a balance between training SMART and HARD.