I take a tonne of supplements and they definitely do help (except creatine, my stomach always rejects it for some reason), but I also eat at least 30% above maintenance spread out over 5-6 meals on workout days, just to give you an idea. I always try to get 8-9 hours of sleep every day otherwise my performance in lifting goes to stuff for the next day. When I go to the gym I know exactly what lifts I'll be doing, how much weight and reps on warmups/work sets I'll be doing, everything right down to which rack and bar I need to use to get the right grip. And on off days, my cardio consists of 50 burpees and 100 squats in under 6 minutes, and I always get above 50 pull-ups and 50 chin-ups (each) total every day. Supplements are basically just that, supplements, especially compared to all the work you have to do to get any gains over months and eventually years of time.