I'm 32 and My knees were never the best to begin with, I'd played football as an offensive lineman, since I was 10 years old, pop warner through varsity. That I think messed up my knees but I was still able to work out, jog, go hiking etc... with no real issues, except some lasting minor pain and aches. About 5 months ago I wrenched the hell out of my left knee, by being stupid. Anyways, my doctor said I needed to let it rest and stay off it as much as possible and to wear a knee brace. It hurt to walk, go upstairs, sit with my knee bent. After a few months I was able to take the brace off and it didn't hurt to walk or sit down. However, walking up stairs there was always a twinge. I had stopped doing legs at the gym and stopped running as well. I would use the elliptical for cardio, since its very low impact. I finally got the go ahead from my doctor to do legs but to keep it light weight. So, I tried doing legs at the gym, my right is still strong as hell was able to do everything, but my left couldn't do anything without extreme pain, except leg curls. I like to do my legs individually so one leg doesn't compensate for the other legs weakness. As such leg extensions, leg press, toe raises, squats, even lunges all hurt like a SOB. Just doing any weight at the gym was agonizing so I stopped. I mean I couldn't even do standing lunges let alone walking. I could go jogging for a couple miles and my knee would hurt a little afterwards but it was fine. Some friends recommended this so I bought it at the OneStop Nutrition next to the gym. Well after I would say 3-4 weeks the pain started going away. I've been taking for 1.5-2 months now and my left knee is almost as good as new. I can finally do lunges, light squats, and just as much weight for extensions and leg press as my right leg can, with very little pain in my left leg. There is still pain during and after but it has almost gotten to be non-existent, I assume if I keep taking this it will go away completely and I hope so. As it is I am just glad the pain has gone away so much. Oh, and my right leg has no issues with anything anymore. Hopefully my left leg will soon be in the same boat. Read more