Abstract
High-intensity interval training (HIIT) has gained attention for its potential to improve health outcomes across various conditions. Thus, the aim of the study was to summarize studies on HIIT to understand its effects on various health outcomes. We conducted an umbrella review of systematic reviews and meta-analyses. PubMed, Cochrane Database of Systematic Reviews, EMBASE, Scopus, CINAHL, and Web of Science were searched for relevant articles. The experimental group was subjected to HIIT with or without treatment, while the control group comprised individuals who underwent alternative forms of training or were non-exercisers. Included studies were systematically analyzed for effects of HIIT and cardiovascular, respiratory, metabolic, neurological, gastrointestinal, immunological, and survival-related outcomes. Of 336 identified systematic reviews, 133 were included in the final analysis. HIIT was found to confer significant physiological benefits, including improvements in body composition, cardiovascular and metabolic parameters, and mental health outcomes. Studies demonstrated the efficacy of HIIT across diverse patient populations, with comparable or superior effects to moderate-intensity continuous training in conditions such as diabetes, cardiovascular diseases, neurological, oncologic, and pain-related disorders. Our review highlights the potential of HIIT as a time-efficient intervention for improving health outcomes and managing chronic diseases. However, interpretation of the results should be performed cautiously due to the heterogeneity observed. High-intensity interval training shows promise as an effective strategy for managing chronic diseases among diverse patient populations. Future research should focus on refining HIIT protocols and elucidating their long-term effects and sustainability.