The Effect Of A Single Bout Of Sub-symptom Threshold Aerobic Exercise On Executive Function In Acutely Concussed Athletes

PURPOSE: Impaired executive function (EF) and decreased cerebral blood flow (CBF) represent persistent sequelae associated with sport-related concussion (SRC). Notably, healthy controls show an exercise-mediated increase in CBF and EF benefit following a single bout of aerobic and/or resistance exercise. Therefore, engaging in sub-symptom threshold aerobic exercise may serve as an intervention to enhance EF and CBF during acute SRC recovery. This study examined the effect of sub-symptom threshold aerobic exercise on EF and CBF during the acute phase of SRC recovery. METHODS: SRC participants (N = 12) completed an initial cycle ergometer assessment to determine their participant-specific work rate associated with symptom exacerbation. On a separate day, a 20-minute cycle ergometry session at 80% of the heart rate associated with symptom exacerbation was completed. Changes in EF were assessed using an oculomotor task (i.e., antisaccades), and exercise-mediated changes in cerebral blood flow were measured using transcranial Doppler ultrasound to estimate middle cerebral artery velocity (MCAv). RESULTS: A reliable 22 ms (SD = 19) reduction in antisaccade RTs was observed from pre- to postexercise assessments (p < 0.01), and this was associated with an exercise-mediated increase in MCAv (p < 0.05). Moreover, an increase in SRC symptomology was not reported during or after the exercise intervention. CONCLUSIONS: Sub-symptom threshold aerobic exercise is associated with improved EF and increased CBF in individuals with acute SRC and suggests the potential of personalized aerobic exercise for post-concussion cognitive rehabilitation. Natural Sciences and Engineering Research Council of Canada (NSERC)