The Effects of Physical Activity on Bilateral Transfer in Young Adults

Transfer between limbs in younger adults is typically asymmetrical, with greater changes observed in one limb following practice with the other limb, depending on the controlling hemisphere (Pan & van Gemmert). This asymmetry is linked to lateralized hemispheric control of movement (Sainburg), irrespective of high (HPA) or low (LPA) levels of physical activity (McGregor et al.). Acute exercise affects motor skill transfer (Neva et al.). The purpose of this study was to examine the effects of reported chronic physical activity level on bilateral transfer in young adults. Fifty young right-handed participants (18-30) were grouped by physical activity level and randomly assigned a training limb. Individuals performed a 30° visual rotation drawing task. Pretest established baseline performance of each limb, followed by 40 practice trials on the assigned limb. Post-tests mirrored pretests assessing changes. HPA improved movement time (MT), normalized jerk (NJ), trajectory length (TL), and initial direction error (IDE) in the dominant limb following non-dominant practice (p < .05). LPA showed symmetrical transfer for IDE (p < .05), with improvements in either limb following training. HPA elicited asymmetric transfer of motor planning parameters. LPA elicited symmetric transfer, indicating compensatory ipsilateral hemispheric control, like older adults (Cabeza et al.).