Habitual exercise evokes fast and persistent adaptation during split-belt walking

Abstract

Changing movement patterns in response to environmental perturbations is a critical aspect of gait and is related to reducing the energetic cost of the movement. Aerobic exercise improves energetic capacity for submaximal exercise and may affect how people adapt movement to reach an energetic minimum. The purpose of this study was to determine whether differences in recreational aerobic exercise training influence gait adaptation in healthy young adults. Active (n=19) and Inactive (n=13) young adults walked on a split-belt treadmill with one belt moving twice the speed of the other belt for 10 minutes. Step length asymmetry (SLA) and mechanical work done by each leg were measured over each stride. Nonlinear mixed effects models compared the timecourse of adaptation between Active and Inactive young adults, and t-tests compared net work at the end of adaptation between Active and Inactive young adults. Compared to Inactive young adults, Active young adults initially adapted SLA and positive work by the fast leg quickly, and continued to gradually adapt them over the duration of split-belt treadmill walking. There was no effect of exercise on adaptation of negative work by the fast leg or on net mechanical work. Young adults who regularly participate in aerobic exercise respond more quickly to the onset of a perturbation, and throughout the perturbation they continue to explore movement strategies to reduce energetic cost.