Aim 1: Determine whether early sub-threshold aerobic exercise (i.e., light limited duty added to the current Department of Defense Progressive Return to Activity [DoD PRA]) protocol speeds return to duty (RTD), improves clinical recovery, and protects against risk of persistent post-concussive symptoms(PPCS).~Hyp 1.1: Aerobic exercise+DoD PRA early after injury speeds RTD and improves clinical recovery in CSM compared to the DoD PRA protocol alone. Hyp 1.2: Early aerobic exercise+DoD PRA protects against risk of PPCS in concussed service members (CSM) at 1 and at 3 months post-injury versus the DoD PRA protocol alone.~Aim 2: Determine whether a march-in-place test informs clinical decision-making and contributes to RTD decisions.~Hyp 2.1: The degree of early exercise intolerance on the Buffalo Concussion March Test will correlate with the development of PPCS and inform clinician decision making on RTD.~Aim 3: Determine how aerobic exercise improves concussion recovery. Hyp 3.1: Aerobic exercise improves abnormal autonomic nervous system regulation in CSM.~Hyp 3.2: Aerobic exercise reverses changes in salivary brain-derived neurotrophic factor (BDNF), BDNF-related micro RNAs, and inflammatory-related miRNAs seen in CSM.~Hyp 3.3: Aerobic exercise improves mental health (i.e., anxiety/depressive symptoms, sleep, resilience, self-efficacy, morale) in CSM.
Our primary objective is to show that early, personalized aerobic exercise treatment safely improves concussion recovery, speeds RTD, and reduces persistent symptoms in CSM. Our secondary objectives include demonstrating the clinical utility of our March-in-place test and determining fundamental mechanisms for the effect of exercise rehabilitation on concussion recovery.