Author(s): GUO, L., YUAN, W., LIU, N., LI, W., SHU, C., SHEN, Z., HOU, Z., Institution: DALIAN UNIVERSITY OF TECHNOLOGY, Country: CHINA, Abstract-ID: 1242

INTRODUCTION: While high intensity interval training (HIIT) has gained increasing popularity as a time-efficient exercise stimulus to promote health and fitness, studies examining its effects on cognition, especially higher-order executive functions, are rather limited [1]. The parameters of a HIIT protocol, including session volume, intensity, and work-to-rest time ratio, have the potential to impact executive function [2]. However, there is still a scarcity of research in this particular domain. Therefore, the aim of the current study is to explore the effects of various HIIT protocol parameters on executive function.
METHODS: Thirteen sedentary women (age: 20.08±1.32 years; BMI: 21.58±2.30 kg/m2) participated in a randomized crossover trial. The trial included three pairs of HIIT protocols that varied in training volume (V), work intensity (I), and work-to-rest time ratio (W/R). The protocol pairs were as follows: A) high volume (HV) for 30 minutes vs. low volume (LV) for 20 minutes, B) high intensity (HI) (over 85% to 95% of maximum heart rate) vs. low intensity (LI) (75% to 85% of maximum heart rate), C) W/R of 1:1 vs. W/R of 1:2. Before and after each condition, the participants completed several cognitive tasks, including the Stroop test (ST), N-back task (NT), and more-odd shifting (MS), to assess their executive function.
RESULTS: Compared to the pretest, significant differences (p<0.05) were observed in reaction time (RT) for ST across all the training conditions after acute HIIT training, while greater change in accuracy (AC) only induced by HV (p<0.05). For NT, most protocols resulted in a significant decrease in RT (p<0.05), except for HV, HI and W/R (1:2) in the 1-back test. Additionally, significant increases in the AC of 2-back test were found for the three groups, excluding HV and W/R (1:2). In MS, there was a significant decrease (p<0.05) in RT for subgroups. In addition, in group A, HV had greater effect on the AC of ST (Congruent: P=0.004, η2=0.298; Incongruent: p<0.001, η2=0.511), and HV showed more improvement (p=0.035, η2=0.173) in the RT of MS. In group B, HI demonstrated better result in the RT of MS (p=0.014, η2=0.227).
CONCLUSION: HIIT exercise has been shown to have a positive impact on executive function. However, the specific effects can vary depending on the different protocols used. This studys findings suggest that acute HIIT sessions with higher levels of training volume and/or intensity may be associated with greater improvements in executive function, particularly for sedentary young women. These results highlight the importance of considering the specific parameters of HIIT protocols when designing exercise interventions aimed at enhancing executive function. Further research is needed to better understand the optimal HIIT protocols for maximizing the benefits on executive function in different populations.
References:
1. Jacob et al., Sports Med, 2023.
2. Hsieh et al., J Sports Sci, 2021.