Author(s): WU, C.T., GUERRA, G.1, KAO, S.C.2, BRISEBOIS, M.F.3, WANG, C.H.4, Institution: ST. MARY'S UNIVERSITY, Country: UNITED STATES, Abstract-ID: 934

Introduction:
Based on findings from systematic reviews and meta-analyses, acute exercise (e.g., aerobic or resistance exercise) improves inhibitory control. However, a popular fitness trend, CrossFit®, has not been widely studied regarding its effect on inhibitory control. CrossFit® is a high-intensity functional training (HIFT) program that stresses the cardiorespiratory and muscular systems through complex, multi-joint movement patterns with minimal rests in-between sets. Wilke (2020) found that a 15-minute HIFT exercise bout improved working memory. However, the effect of HIFT on inhibitory control remains unclear. The purpose of the current study was to assess inhibitory control after a single bout of HIFT exercise.
Methods:
Fifteen healthy young adults (age: 20.6 ± 1.3 yr., female n = 8) underwent two 15-minute sessions: (1) HIFT condition, which was comprised of 6 exercises commonly practiced in most CrossFit® gyms: burpees, inverted rows, dumbbell push presses, squat jumps, dumbbell snatch, and leg raises. These were performed in a circuit with repeating 20-second all‐out training bouts and 10-second rest periods; and (2) a control condition involving reading neutral magazines provided by the investigator. Before and after the sessions (counterbalanced), the flanker task was applied to evaluate the differential changes in inhibitory control across conditions. Statistical analyses were conducted for response accuracy (ACC) and reaction time (RT) using a 2 (Time: pre-intervention, post-intervention) × 2 (Treatment: rest, HIFT) × 2 (Congruency: congruent, incongruent trials of the flanker task) multivariate repeated-measures ANOVAs.
Results:
Analysis on ACC showed a main effect for Congruency, with higher ACC for the congruent trials (99.4 ± 0.5%) than incongruent trails (96.9 ± 2.1%). Analysis of RT revealed a Time effect (F (1, 14) = 10.5, p = 0.006, η2 = 0.43) and a Congruency effect (F (1, 14) = 58.6, p < 0.001, η2 = 0.81) which was superseded by an interaction of Time × Treatment × Congruency (F (1, 14) = 5.6, p = 0.032, η2 = 0.29). Decomposition of this three-way interaction showed an interaction of Time × Congruency (F (1, 14) = 4.9, p = 0.043, η2 = 0.26) only for the CrossFit treatment, with decreased RT at post-intervention relative to pre-intervention for both congruent trails (t (14) = 2.8, p = 0.006) and incongruent trials (t (14) = 3.1, p = 0.004) .
Conclusion:
These results suggest that HIFT may benefit cognitive function, specifically the overall processing speed involving inhibitory control, in healthy young individuals. Incorporating HIFT into routine physical activity regimens may offer cognitive benefits in addition to traditional fitness improvements.
References:
Wilke, J. (2020). Functional high-intensity exercise is more effective in acutely increasing working memory than aerobic walking: an exploratory randomized, controlled trial. Scientific Report, 10, 12335.