Time-Course Analysis of Cognitive Benefits Following Self-Stretching Using a Self-Control Design: Evidence from Stroop, N-Back, and Memory Tasks

<b>Background:</b> While physical activity has been shown to enhance cognitive function, little is known about whether stretching, a low-intensity, accessible form of exercise, can elicit similar benefits, particularly over time. The study adopted a self-control (within-subject) design. <b>Purpose:</b> This study aimed to investigate the time-dependent effects of self-stretching on cognitive performance in healthy adults. <b>Methods:</b> Thirty healthy participants performed a self-stretching protocol targeting the neck and shoulder muscles. Cognitive performance was assessed in terms of attention (Stroop test), working memory (N-back test), and short-term memory (digit span-based memory test) at baseline, and at 10, 20, and 30 min post-intervention. Paired t-tests and Wilcoxon signed-rank tests were used to analyze changes in cognitive performance. One-way ANOVA was conducted on baseline data to confirm the homogeneity across the three measurement groups. <b>Results:</b> One-way ANOVAs confirmed no significant baseline differences among the three groups in any cognitive measure (<i>p</i> > 0.05). Stroop test results showed a significant reduction in reaction time at 10 (<i>p</i> = 0.01) and 20 min (<i>p</i> = 0.02) post-stretching, indicating an improvement in information processing speed. The effect size (Hedges' g) for this improvement was very large (-1.01) at 10 min and large (-0.87) at 20 min. However, no significant improvements were observed in Stroop accuracy scores, memory performance, or N-back task results at any time point. <b>Conclusions:</b> Self-stretching produced short-term improvements only in reaction time during attention tasks, while no changes were observed in memory or working memory accuracy. These findings suggest that stretching may offer brief, task-specific benefits related to processing speed rather than broad cognitive enhancement.