The study I found was called: Swinging into thought 

The participants were 52 university students 

The interventions used were stretch breaks, and movement breaks on a fixed interval schedule. These breaks were given during a difficult cognitive task. 

The design used was two groups with differing treatments (movements). There was no control group, and no reversal. 

The results were that students who completed the movement breaks did better at the task than the stretching group.