I'm not the most experienced guy, been working out seriously only for the last 2 years but I limited my supplements to vitapacks, creatine, glutamine and of course protein, tried a lot of other supplements but found that the Return on investment was questionable. Some time I feel slugish when I first get to the gym but after my 10 min at 8 mph on the threadmill I'm motivated and ready to push it harder than yesterday! Good luck!!