The Blast Strap Face Pull is performed just like any other face pull, by grabbing the handles and pulling your hands back, keeping them in line with your eyes/face. The only difference is that you will be moving towards the anchor point, versus your body staying in place.
To perform the exercise, grab a set of blast straps that are anchored somewhere above your head. You don't want it to be ridiculously high. If you have a very high anchor, you're going to need to stand way back from the anchor point. Keeping the back of your hands pointed at the ceiling, pull the elbows back while keeping them above shoulder level. If you let the elbows drift down, it becomes a lat exercise. Pull your elbows back until your hands are in line with your face, pause for a second, and then return to the starting position.
If you need more or less resistance on the exercise, you can move your feet closer to, or further from, the anchor point accordingly. Perform this exercise for 3-5 sets of 8-20 reps.
