Effects of High-Intensity Interval Training on Executive Function in physically inactive population: A Systematic Review and Multilevel Meta-Analysis

Physical inactivity has been widely demonstrated to be associated with a range of adverse health outcomes. Beyond cardiometabolic risks, increasing attention has recently been directed toward its potential negative effects on cognitive function, particularly executive functions. Executive functions, as a key component of higher-order cognition, encompass processes such as inhibitory control, working memory, and cognitive flexibility. These functions are fundamental for performing complex tasks, maintaining learning and work efficiency, and supporting psychological well-being. Prolonged physical inactivity may adversely affect executive functions through mechanisms including reduced cerebral blood flow, impaired neural plasticity, and altered neurotransmitter regulation. Physical exercise is regarded as an important non-pharmacological strategy for improving executive functions. Among different exercise modalities, high-intensity interval training (HIIT) has gained increasing interest in recent years due to its high time efficiency, strong cardiopulmonary stimulus, and pronounced neurophysiological responses. Accumulating evidence suggests that HIIT may exert positive effects on executive functions by promoting the release of brain-derived neurotrophic factor, improving cerebral hemodynamics, and enhancing activation of the prefrontal cortex. However, existing studies examining the relationship between HIIT and executive functions have predominantly focused on healthy adults, older adults, or physically active populations, with considerable heterogeneity in participant characteristics, training protocols, and comparator conditions. To date, there is a lack of systematic reviews and meta-analyses specifically targeting physically inactive populations to comprehensively evaluate the effects of HIIT on executive functions, particularly in comparison with non-exercise control conditions or moderate-intensity continuous training. Therefore, a systematic synthesis and quantitative analysis of available randomized controlled trials is warranted to clarify the effects of HIIT on executive functions in physically inactive individuals and to determine its relative advantages.