A single bout of exercise improves motor memory

Abstract

Regular physical activity has a positive impact on cognition and brain function. Here we investigated if a single bout of exercise can improve motor memory and motor skill learning. We also explored if the timing of the exercise bout in relation to the timing of practice has any impact on the acquisition and retention of a motor skill. Forty-eight young subjects were randomly allocated into three groups, which practiced a visuomotor accuracy-tracking task either before or after a bout of intense cycling or after rest. Motor skill acquisition was assessed during practice and retention was measured 1 hour, 24 hours and 7 days after practice. Differences among groups in the rate of motor skill acquisition were not significant. In contrast, both exercise groups showed a significantly better retention of the motor skill 24 hours and 7 days after practice. Furthermore, compared to the subjects that exercised before practice, the subjects that exercised after practice showed a better retention of the motor skill 7 days after practice. These findings indicate that one bout of intense exercise performed immediately before or after practicing a motor task is sufficient to improve the long-term retention of a motor skill. The positive effects of acute exercise on motor memory are maximized when exercise is performed immediately after practice, during the early stages of memory consolidation. Thus, the timing of exercise in relation to practice is possibly an important factor regulating the effects of acute exercise on long-term motor memory.

Figure 1. Phases of the experiment.

Figure 2. The visuomotor accuracy-tracking task (AT).

(a) Subjects were seated in front of a computer screen with the right forearm placed in a molded rigid custom-made arm support. (b) The forearm was positioned in a neutral semi-prone position. (c) The main application window contained a target consisting of a fixed double sine wave curve (red) that subjects had to track with the torque signal (white). (d) The second window provided visual feedback on the performance of the AT task by displaying a series of white dots on a coordinate axis.

Figure 3. Performance of the visuomotor accuracy-tracking task (AT) during acquisition and retention.

A. Performance was measured as the average root mean square (RMS) value of the error distance between the subject's torque signal and the displayed target. All groups showed similar performance in the rate of acquisition of the motor skill (p = 0.81) measured throughout the blocks 1–3 of practice. Each data point represents the average of each single trial. B. Performance was measured as the average root mean square (RMS) value of the error distance between the subject's torque signal and the displayed target. Overall differences among groups in the retention of the motor skill were found (*). The PRE and POST groups showed a better retention of the motor skill than the CON group 24 hours and 7 days after practice (**). POST also showed a better retention than PRE 7 days after practice (***). Data are presented as means and the error bars are standard error of the mean. All comparisons yielded a p value <0.001.