Guess what happened to their performance? Some of their one rep maxes grew by up to 20%. Not bad for a substance which had no active ingredients, except the ability to convince the mind that it CAN do it!
Certainly something for you to consider and take in to your next workout.
Now I do have to come clean because I did forget to mention one thing. Just six days ago I did start stacking Kaged Muscle Creatine HCL which is the first creatine I've used in about four years. My body has never agreed with creatine before.
I'm bigger, fuller and stronger. So maybe the 25% increase in strength wasn't all in the mind after all, but there was undoubtedly an element of both.