The rate of rotation decreases. Conservation of angular momentum.
Work Step by Step
This situation is similar to the one shown in Figure 8.52, but in reverse. When you crawl outward, you are moving mass away from the axis of rotation, which increases the rotational inertia of the system. No external torques act on the system (turntable + you), so angular momentum is conserved. The product of rotational inertia and rotational speed stays constant. Since the first went up, the second must go down.