You can capture the movement only through a couple of lines. A handful of precise strokes can tell more story than a complete drawing. If a couple of moments is enough for you to get the story right, and you are able to take this story to paper without losing anything - you will get a perfect life drawing.
Take, for example, Wilhelm Busch, - famous German artist, famous for his caricatures, - who knew everything about the power of the precision. His sketches are minimalistic, yet they tell about the gesture and movement anything the viewer needs to know to feel those movements. Wedges help direct the energy, and arcs help maintain those directions. There isn't enough clarity in figures, but you need no effort to guess who are they. There is no time for details - only gesture and silhouette matters. All those moments the artist had to capture those drawings he had spent wisely.