The hypothesis
My hypothesis is that physical effort and working-memory practice might reinforce each other when they happen together. The prototype lets me explore that possibility; establishing a benefit would require a separate study.
The proposed task
A spoken number maps to a movement. Instead of executing the newest cue, recall and perform the movement from N cues earlier while keeping track of the incoming sequence.
What the prototype contributes
A practical setting to explore cue pacing, memory load, and work/rest timing. The supporting document describes the rationale and proposed protocol; it does not report experimental results.
What a test could examine
A future comparison could separate combined, sequential, and single-task conditions, measuring task performance and adherence. Better performance on the practiced task would need to be distinguished from broader transfer.