they arent bad for a 19 year old. there are is no shutdown with the liquid gels brother. i bought them, used them and got good strength gains, but i do have knee pain from time to time now. ( my leg presses went up in the weight significantly). some would say to do squats but that **** hurts my knees. anyways, if you get x-factor throw in some cissus. I really should have done that with the halo- liquid gels. and btw, they are too damn expensive, go with the x-factor.