Does an individual's fitness level affect baseline concussion symptoms?

CONTEXT: Variables that may influence baseline concussion symptoms should be investigated. OBJECTIVE: To evaluate the effect of physical fitness on self-report of baseline concussion symptoms in collegiate athletes and students. DESIGN: Controlled laboratory study. PATIENTS OR OTHER PARTICIPANTS: A total of 125 undergraduates, including 95 collegiate athletes and 30 recreational athletes (83 males, 42 females). INTERVENTION(S): Participants completed the Standardized Concussion Assessment Tool 2 (SCAT2; symptom report) at baseline, within 10 minutes of completing the Leger test, and within 24 hours of the initial baseline test. The Leger (beep) test is a shuttle-run field test used to predict maximal aerobic power. MAIN OUTCOME MEASURE(S): The total symptom score on the SCAT2 was calculated and analyzed with a repeated-measures analysis of variance. A linear regression analysis was used to determine if 3 variables (sport type, sex, or fitness level) accounted for a significant amount of the variance in the baseline symptom report. RESULTS: Participants reported more symptoms postactivity but fewer symptoms at 24 hours compared with baseline, representing a time effect in our model (F2,234 = 47.738, P < .001). No interactions were seen among the independent variables. We also found an effect for fitness level, with fitter individuals reporting fewer symptoms at all 3 time intervals. The regression analysis revealed that fitness level accounted for a significant amount of the variance in SCAT2 symptoms at baseline (R (2) = 0.22, F3,121 = 11.44, P < .01). CONCLUSIONS: Fitness level affected the baseline concussion symptom report. Exercise seems to induce concussion symptom reporting, and symptom severity may be a function of an athlete's level of conditioning. Sports medicine professionals should consider an athlete's level of fitness when conducting baseline concussion symptom assessments.