Learning an energy-demanding and biomechanically constrained motor skill, racewalking: movement reorganization and contribution of metabolic efficiency and sensory information.

This study investigated how novices learn an energy demanding and biomechanically constrained task like racewalking. The first aim was to examine if movement reorganizes according to some fundamental strategies, proceeding in different stages (Newell, 1985). The second aim was to investigate the link between movement reorganization, metabolic efficiency and perceived exertion. Seven participants undertook seven racewalking learning sessions on a motorized treadmill, with increased velocity as the experiment progressed, in order to reach a goal performance speed of 10 kmh(-1). Peripheral/central perceived exertion ratings, kinematic and metabolic data were collected during the 1st, 4th, 6th and 7th session. Repeated-measures (Learning Session×Speed) ANOVAs on kinematic data showed a proximal-to-distal directional trend in movement reorganization, with significant practice-related changes in pattern coordination and decreased variability. Early movement reorganization occurred at the 1st session ("coordination stage") and progressed until the 4th session ("control stage") to reach a plateau. In contrast, metabolic efficiency and peripheral perceived exertion continued optimizing until the last session, probably occurring in concurrence with the control stage. Peripheral perceived exertion presented the highest correlation with the global movement reorganization variables suggesting that it could play a key role in guiding movement reorganization in the learning process, improving efficiency as a result.