This exercise actually consists of five different exercises, that all work on several aspects of your drawing technique. The main focus throughout them is on flow and on a smooth line, two things that come from drawing from your shoulder. And as you may know, smoothness and flow will seriously improve your ability to capture motions and life in your sketching and in your drawing.
Some continuous work with these exercises will have you seeing great improvements to the ease and the life of your drawings.
I picked these exercises up from the polish artist Andre Pijet, and I absolutely love them! Not alone are they immensely useful, they’re also fun to do, and as you might know, I am a big fan of making it fun to draw. The practice as well as the actual drawing sessions. Win-win!
Personally I have found, that my sketching in particular, has improved a lot since I began working with these exercises. And since the sketches obviously are the foundation for everything that comes after, this translates to overall improvements! Awesomeness all around!
Not much else to say about this. Give these exercises a try, and feel your arm liberate itself as you incorporate the motions into your muscle memory.
Good luck, and happy drawing!