To investigate potential clinical biomarkers for prognosis of return to sport in sport-related concussion.

Predicting time to recovery following sport-related concussion remains a clinical challenge due to the heterogeneous nature of symptoms and recovery trajectories. Previous studies show longer recovery in patients symptomatic at baseline or with increased symptoms during rehabilitation. We evaluated whether early supervised exercise response could serve as a prognostic marker for recovery duration.

A retrospective review of 521 charts was performed. Patients seen within 14 days of injury and undergoing supervised exercise at their first encounter were included. Patients were stratified by time to clinical recovery (<30 days, Recovery Bin 1 or 30–60 days, Recovery Bin 2) and symptom onset during exercise was recorded. Statistical analysis included descriptive analysis, t-tests, and linear regression modeling.

Among eligible patients (n=27), those recovering in <30 days (n=20) tolerated longer exercise before experiencing an increase in headache symptoms than those in the 30-60 days group (n=7) (13.2 vs 6.4 minutes, p = 0.0049). Twelve of 13 patients who exercised ≥9 minutes before headache provocation were in Recovery Bin 1. Linear regression demonstrated a significant association between headache onset timing and time to recovery (Recovery Bin 1 vs 2, p = 0.0075). Other symptoms such as nausea and lightheadedness did not significantly differ between recovery groups. 

Symptom response during early supervised exercise may be a useful prognostic tool for predicting recovery in sport-related concussion. Patients who recovered within 30 days tolerated longer exercise and experienced smaller increases in headache. A threshold effect was observed, as exercising ≥ 9 minutes before headache provocation strongly predicted faster recovery. Nausea and dizziness were not predictive. Findings support further study of exercise-based monitoring to guide individualized recovery.