Context: Determination of return to play (RTP) after sport-related concussion (SRC) is critical given the potential consequences of premature RTP. Current RTP guidelines may not identify persistent exercise-induced neurocognitive deficits in asymptomatic athletes after SRC. Therefore, postexercise neurocognitive testing has been recommended to further inform RTP determination. To implement this recommendation, the effect of exercise on neurocognitive function in healthy athletes should be understood. Objective: To examine the acute effects of a high-intensity intermittent-exercise protocol (HIIP) on neurocognitive function assessed by the Symbol Digits Modality Test (SDMT) and Stroop Interference Test. Design: Cohort study. Setting: University laboratory. Participants 40 healthy male athletes (age 21.25 ± 1.29 y, education 16.95 ± 1.37 y). Intervention: Each participant completed the SDMT and Stroop Interference Test at baseline and after random allocation to a condition (HIIP vs control). A mixed between-within-subjects ANOVA assessed time- (pre- vs postcondition) -by-condition interaction effects. Main Outcome Measures: SDMT and Stroop Interference Test scores. Results: There was a significant time-by-condition interaction effect (P < .001, η2 = .364) for the Stroop Interference Test scores, indicating that the HIIP group scored significantly lower (56.05 ± 9.34) postcondition than the control group (66.39 ± 19.6). There was no significant time-by-condition effect (P = .997, η2 < .001) for the SDMT, indicating that there was no difference between SDMT scores for the HIIP and control groups (59.95 ± 10.7 vs 58.56 ± 14.02). Conclusions: In healthy athletes, the HIIP results in a reduction in neurocognitive function as assessed by the Stroop Interference Test, with no effect on function as assessed by the SDMT. Testing should also be considered after high-intensity exercise in determining RTP decisions for athletes after SRC in conjunction with the existing recommended RTP protocol. These results may provide an initial reference point for future research investigating the effects of an HIIP on the neurocognitive function of athletes recovering from SRC.
The authors are with the School of Health and Human Performance, Dublin City University, Dublin, Ireland.