I bought this at the Gran Fondo Hincapie. I wasn't skeptical. For goodness sake I heard it on the WEDU podcast during the Tour de France. The riders were screaming about its benefits. I read multiple reviews. So skepticism wasn't part of the consideration in buying it. I wondered what it would do for me. In the simplest terms 'an amateur' cyclist who self rewards off of his own PR's on Strava and a high five every now and then on a group ride. This year I bought a new bike, but only trained for 8 weeks leading up to the Hincapie. Last year I rode in the 80 mile and trained really hard for it. This year not so much. AMP Human had been in my 'cart' on the Feed website over and over again thoughout the year, but I never went for it. I was ready or the Hincapie, but not optimum in my preparedness. I credit my outstanding ride to AMP Human. Not only did I finished faster than ever before, I PR'd in 16 of my 24 segments on Strava, and did not feel discomfort in my legs the whole race. I'm excited to actually start training now! I can go much further than ever before. I'm 44 years old, and maybe next year I'll take some age groups:) Just kidding. This product is amazing.