Effects of Low-Volume High-Intensity Interval Training on Cardiovascular Disease Risk Factors and Underlying Mechanisms: Evidence and Perspectives

Background:Time constraint is one of the most frequently reported barriers to regular physical activity, limiting the real-world scalability of traditional moderate-intensity continuous training (MICT) for cardiovascular disease (CVD) prevention. Low-volume high-intensity interval training (LV-HIIT) has emerged as a time-efficient exercise strategy that preserves high relative intensity while markedly reducing total exercise volume and session duration. Objective:This narrative review aims to synthesize current evidence on the effects of LV-HIIT on major CVD risk factors and to integrate potential physiological mechanisms underlying its multi-system benefits, with particular emphasis on population- and protocol-dependent responses. Methods:Relevant randomized controlled trials, systematic reviews, and meta-analyses investigating LV-HIIT in relation to cardiorespiratory fitness, blood pressure, glucose metabolism, lipid profile, body composition, and vascular function were narratively summarized and critically appraised. Results:Across diverse populations, including sedentary individuals, those with overweight or obesity, metabolic dysfunction, and selected clinical cohorts, LV-HIIT consistently improves cardiorespiratory fitness and often reduces systolic blood pressure, with effects generally comparable to MICT despite substantially lower time commitment. In contrast, outcomes related to glycemic control, lipid profile, and body composition show greater heterogeneity and appear more dependent on baseline metabolic status, intervention duration, and protocol characteristics. Mechanistically, LV-HIIT likely induces coordinated central–peripheral adaptations, including enhanced cardiac output, autonomic regulation, skeletal muscle mitochondrial remodeling, improved substrate utilization, and shear stress–mediated endothelial function. Anti-inflammatory and antioxidative effects may further contribute, particularly in metabolically compromised individuals. Conclusions:LV-HIIT represents a pragmatic and time-efficient exercise strategy capable of delivering robust improvements in key cardiovascular risk factors. While benefits for cardiorespiratory fitness and blood pressure are relatively consistent, metabolic and body composition responses require stratification by population characteristics and training design. Future research should prioritize longer intervention periods, standardized LV-HIIT definitions, and mechanistic phenotyping to optimize clinical translation and public health implementation.