I believe that some concepts from yoga can be used in training, especially when working with those who are at high risk for overuse injuries. I have had the pleasure of learning and practicing a form of yoga called Eishens yoga for the past year and a half. This form of yoga is more about proper alignment and learning how to activate muscles that you have not been using or muscles that are not as active as they used to be. This could happen for many different reasons but one of them is because of how well our bodys adapt to movement. I have had very good success with using a few different poses mixed in with both active and passive stretching. However when I have someone in a pose they are not trying to relax, it is the opposite actually, I try to use feedback through touch to help activate muscles and align the body. I was very skeptical of yoga myself before I started to learn more about eischens yoga and was still skeptical the first few months of trying it but I have seen some very good results in myself, my wife, and those that I train, including the athletes I work with at USD. I have had people tell me that yoga is the whole lifestyle thing and what I am doing is not yoga and that is fine with me because if I find a part of something that I like but do not like the whole, guess what, I am going to use the part that I feel is benificial. If I was to only use the whole of everything I would be nowhere because I dont agree with everything the NSCA does, I dont agree with everything crossfit does, I dont agree with everything in the RKC, and I dont agree with everthing that is a part of yoga but I use some things from all of them and from other things as well. The point is that I think we shouldnt just be like F Yoga only because of what someone else tells us what it should or shouldnt be. There are great things to learn in all areas! For weightlifting I feel it can be benificail because you need to be flexible but active at the same time (ex. catch of a clean or snatch) and Eischens yoga fits in well with this demand of the sport.
P.S. I am also continually working on how to incorporate the poses into workouts and by no means feel I have figured it all out, it has been very interesting trying to tie them into full team workouts and most of the athletes here have really been liking it.