Here is a great exercise! I think of this as the opposite of a swing (in terms of mechanics), but requiring the same athleticism, coordination, and timing as the swing. Most people will find their shoulders will fatigue first in this exercise, because of how much they have to be used to control the centrifugal forces of the pendulum. You will also find it necessary to stay braced through you abdominals and to move quickly in your squat, otherwise the timing will be too dysfunctional. I like to use this exercise during timed sets, such as intervals or circuits. Like the swing, it will likely get your heart rate up quickly.