A big part of being able to move laterally from side to side quickly is having loose hips. If you are tight in your core and hip area, you wont be able to get low in an athletic stance and push off in either direction to cut off the offensive player. This basketball exercise is going to work on opening up the hips, and also strengthening them so that the player can stay low in a defense stance for a longer period of time.
The resistance band hip abduction slide exercise is going to resemble a defensive slide, but with a lot more exaggeration on the movements. With the resistance band it will keep constant pressure on the muscles, and really make them work. Along with this exercise being great for improving athleticism, it is also great for helping with injury prevention. It is a must add to your basketball training regiment.