High-Intensity Interval Training Improves Inhibitory Control and Working Memory in Healthy Young Adults.

Abstract

High-intensity interval training (HIIT) has emerged as a time-efficient mode of exercise. However, there is limited evidence that HIIT improves inhibitory control and working memory (WM) more than moderate-intensity continuous exercise (MICT). This study aimed to explore the effects of HIIT, moderate-intensity interval exercise (MIIT), and MICT on inhibitory control and WM in healthy adults. Twenty-five healthy college students (21.04 ± 2.44 years; 14 females) were recruited to complete HIIT, MIIT, MICT, and a resting session (CON) for 15 min in a randomized crossover design. The HIIT protocol comprised three 3-min bouts at 90% of the maximum heart rate (HR_max) with 2 min of active recovery at 70% HR_max. The MIIT protocol comprised three 3-min bouts at 70% HR_max with 2 min of active recovery at 50% HR_max. A volume-matched MICT protocol was applied at 70% HR_max. The Stroop and 2-back tasks were used to evaluate inhibitory control and WM in post-trials, respectively. Response times (RTs) of the Stroop task significantly improved on the congruent condition in the HIIT session compared to the CON session (p = 0.004, Cohen's d = 0.64), on the incongruent condition in the HIIT session compared to MICT (p = 0.049, Cohen's d = 0.42) and CON (p = 0.023, Cohen's d = 0.49) sessions, and on the neutral condition in the HIIT session compared to MIIT (p = 0.029, Cohen's d = 0.47) and CON (p = 0.012, Cohen's d = 0.55) sessions. Hits in the 2-back task increased significantly following HIIT compared to MIIT (p = 0.041, Cohen's d = 0.43), MICT (p = 0.02, Cohen's d = 0.5), and CON (p = 0.006, Cohen's d = 0.6). We concluded that a single bout of HIIT effectively improved inhibitory control and WM in healthy adults. These findings support the practical implication of HIIT being beneficial within a short time for enhancing inhibitory control and WM in clinical populations.