Gestures can have many purposes: warm-up, expressive exploration, form studies, or even basis for skeletal or muscular studies. They can be the loosest of scribbles or focused surgical strikes of lines. They are probably the most honest of drawings since they are more from the heart than the head. We feel, we empathize, we react on a visceral level rather than a thoughtful considered one. An most of all, they are a singular individual signature.
All that said, I came across this image of variations on three gestures. Each began with just some quick lines that reacted to the pose. From those lines I chose to explore the simple form of boxes, the nature of the skeleton within a pose, and finally a gesture developed into the muscular anatomy of the figure in that pose.
It's a great exercise. I encourage you to try it.