High-Intensity Aerobic Exercise Enhances Motor Memory Retrieval

Introduction: In previous work, acute high-intensity aerobic exercise benefited continuous motor sequence task learning. As memory processes underlying motor sequence learning vary between tasks involving continuous and discrete movements, the objective of the current study was to determine whether the beneficial effects of acute aerobic exercise generalize to the learning of a discrete motor sequence task.

Methods: Sixteen young healthy individuals practiced a discrete motor sequence task preceded by either a period of rest or a bout of high-intensity cycling. Participants moved a cursor with a computer mouse to a series of discretely presented targets on a screen. Target presentation followed either a repeated or a random sequence, which allowed the evaluation of implicit sequence-specific motor learning. The change in movement response time over practice (△-ACQ) and from practice to a 24-h "no-exercise" retention test (△-RET) and the rate of improvement over practice (α-ACQ) and during the retention test (α-RET) were calculated.

Results: α-RET was greater for the repeated sequence than random sequences after aerobic exercise (P = 0.01), but not rest (P = 0.33). Further, α-RET for the repeated sequence was greater after aerobic exercise than for either sequence (repeated, random) in the rest condition (P ≤ 0.01). There were no differences between sequences and/or conditions for △-ACQ, △-RET, or α-RET (P ≥ 0.57).

Conclusion: Our findings show a positive effect of acute high-intensity aerobic exercise on implicit discrete motor sequence learning. Performing exercise before practice increased the rate of improvement at a 24-h delayed retention test, suggesting an effect on the rate of motor memory retrieval. Pairing acute aerobic exercise with motor practice may facilitate learning of discrete movement sequences in sport or rehabilitation settings.