At the end of the Pull, comes the Finish phase. You should be completing your stroke underwater by pushing all the way past your hip, with your thumb able to brush your thigh as you exit the water elbow first. It is critical to finish the stroke off with a hyperextended wrist, so that your palm is still facing directly behind you. If your palm is facing the sky upon exit, the upward force on the water will have applied downward pressure on your hips and increased drag.
Palm facing directly behind you
Elbow exits water first
Thumb able to brush thigh upon exit