The acute influence of boxing on brain health parameters in university amateur boxers

Abstract

The present thesis investigated the acute influence of amateur boxing on brain health parameters across two separate studies. The first study examined 20 university boxers visuomotor performance and neurocognitive function before and after 3 rounds of competitive amateur boxing. Visuomotor performance was assessed via a computer guided precision grip task, both with and without visual feedback, whilst neurocognitive function was assessed via a revised SCAT5 questionnaire and balance task. Boxers presented with no difference in average force or reaction time in both precision grip tasks, although performance error was greater after boxing when compared to pre boxing measures in the visual feedback precision grip task (P<0.05). Neurocognitive function was not influenced by the boxing intervention, but verbal fluency (task included in SCAT5) increased (P<0.05). Balance errors were greater after boxing when compared to pre-boxing measures (P<0.05). Boxers averaged 58 punches to the head, though these data did not correlate to any of the brain health outcomes measured (P>0.05). These findings provide insight into the acute effects of sub-concussive head impacts on amateur boxers. The second study investigated 18 university amateur boxers brain health parameters after sparring when compared to a seated control and boxing training with no head impacts. Cerebrovascular health was assessed via cerebral autoregulation (orthostatic stress via squat-stand manoeuvres and transfer function analysis) and cerebrovascular reactivity (breath-holding and hyperventilation procedures), using transcranial Doppler sonography. Visuomotor control (precision grip task with and without visual feedback) and neurocognitive function (SCAT5 and balance tasks) were also measured as in study 1. Head impacts were recorded by video footage and acceleration of the punches was measured via wrist-worn accelerometers. Boxers demonstrated a delayed cerebral autoregulatory response to orthostatic stress without concomitant changes in cerebrovascular reactivity after amateur boxing. We observed no change to balance or any other measures of neurocognitive function or visuomotor performance after three rounds of boxing. Boxers received an average of 40 punches to the head, resulting in an average accumulative acceleration of 290 g. This is the first study of its kind and highlights that alterations in indices of cerebrovascular integrity may be present in the immediate aftermath of boxing. Further work is now needed to understand the time course of recovery, and whether these acute changes lead to chronic differences between those who do and do not box.