The effect of an acute bout of exercise on implicit sensorimotor adaptation

Recent studies have found that aerobic exercise improves sensorimotor adaptation. For instance, adaptation to an abruptly-presented 45° visuomotor rotation is improved if preceded by an acute bout of exercise. Still, it is known that adaptation is driven both by an explicit (cognitive) process as well as an implicit process. Given that exercise is known to benefit cognitive function, it remains an open question whether exercise selectively improves implicit adaptation. Here we tested this hypothesis, using a paradigm known to isolate implicit adaptation. In a within-participant design, participants (n = 26) had to reach toward a target, while being pseudo randomly exposed to CW or CCW 30° visuomotor rotations. Implicit adaptation was assessed by the involuntary bias in hand direction that follows a rotated trial, called post rotation bias (PRB). On separate days, participants performed 180 trials before (PRE) and after (POST) a period of exercise, or a period of rest. The exercise bout consisted of 20 min of moderate intensity cycling, which has previously been shown to benefit performance in cognitive and adaptation tasks. Results revealed robust PRBs in both conditions and phases, but critically there was an interaction: the magnitude of PRBs was significantly attenuated following rest, but not following exercise. Further analyses revealed that movements were produced significantly faster following exercise, confirming that exercise impacted motor vigor. By showing that an acute bout of exercise prevents the attenuation of implicit adaptation that is observed following rest, these results indirectly suggest that exercise has a positive effect on implicit adaptation.