Changes in neurocognitive function after acute high-intensity exercise: decreasing the biomechanical risk factors of ACL injury

Abstract

Lower baseline neurocognitive ability could be a risk factor for anterior cruciate ligament (ACL) injuries. We investigated the effects of high-intensity exercise (HIE) on neurocognitive function in athletes, and if any changes in neurocognitive function after HIE had effects on an unanticipated cutting motion. Fourteen collegiate female athletes performed a bicycle ergometer HIE exercise at 80% of their heart rate reserve. Neurocognitive function was evaluated by the Stroop interference test (SIT) pre- and post-HIE. Biomechanical variables were captured using a motion analysis system while participants performed side-step cutting tasks in anticipated and unanticipated conditions. Participants were divided into two groups according to the changes in SIT scores after HIE: increased performers (IP; n = 7) and decreased performers (DP; n = 7). The average SIT score of the IP group significantly increased, while that of the DP group significantly decreased after HIE (Paired t-test, p < 0.001). The main effect of HIE using repeated-measures ANOVA, was a significant decrease in peak knee valgus moment (pre: anticipated 0.1 ± 0.1Nm/kg, unanticipated 0.0 ± 0.2Nm/kg; post: anticipated 0.0 ± 0.1Nm/kg, unanticipated 0.1 ± 0.2Nm/kg, p = 0.024) and peak ground reaction force (pre: anticipated 3.3 ± 0.2%BW, unanticipated 3.8 ± 0.2%BW; post: anticipated 3.1 ± 0.3%BW, unanticipated 3.6 ± 0.4%BW, p = 0.035) only in the IP group. Athletes with improved neurocognitive function had decreased the biomechanical ACL injury risk factors during side-step cutting. Improving neurocognitive function may contribute to ACL injury prevention.