There is an increasing number of articles dealing with yoga for athletes. Not distinguished however, is whether the yoga is for a beginner, novice or advanced athlete.
In fact, there is little distinction between some of the yoga poses and some typical beginning strength exercises. For example, in a recent article dealing with yoga for runners, it is recommended that you do the forward bend over which is simply a standing toe touch but with the arms crossed.
Other exercises include the cat in which you assume that all fours position and then raise and lower the torso as much as possible; the inverted V held for a number of seconds; the plank; a long leaning lunge and the pelvic thrust. Note that all of these are exercises. The latter one is a great beginning exercise for strengthening the glutes, hamstrings and lower back not only in rehabilitation but for novice athletes.
Thus we need more distinction between what yoga is used for and how it can benefit an athlete –if it can. As I mentioned, many of these exercises are already being done but they are done in a dynamic fashion. In yoga they are done with a long hold that stretches and does not strengthen.
The bottom line is that Yoga may be good for holding a particular position in sports activities that are static. However, in dynamic sports, as most of them are, you must have movement in the exercise if it is to duplicate what the athlete does in his or her sport.
Thus the exercises described and the use of yoga may be effective in general fitness, especially for beginning and novice athletes, but they have no correlation to dynamic movement or for improving the performance of a higher level athlete.
For more information on training a runner see Explosive Running and Build a Better Athlete.