Abstract
BACKGROUND: High-intensity interval training (HIIT) is an effective exercise for improving physical and psychological function. However, there is an ongoing debate about the effects of HIIT on older adults. This study aimed to examine the effects of HIIT on cardiometabolic health and quality of life in older adults and to provide evidence-based information on the effectiveness of this type of exercise by performing a meta-analysis of randomized controlled trials. METHODS: The ScienceDirect, PubMed, Web of Science, Scopus, Cochrane CENTRAL, CINAHL, and Pedro databases were used to search for all studies conducted up to December 1, 2024. Data were analyzed using Cochrane Review Manager (RevMan) [version 5.4.1] software. Quality of life data was analyzed using standardized mean difference (SMD), while mean difference (MD) was calculated for continuous variables such as heart (bpm), V̇O₂peak (mL·kg⁻(1)·min⁻(1)), 6MWT (m), and gait speed (m/s). In cases where high heterogeneity was observed, the random-effects model was preferred, and in cases where low heterogeneity was observed, the fixed-effects model was preferred. RESULTS: This meta-analysis was performed using data from 11 studies. HIIT intervention groups had statistically significant increases in 6MWT (z = 3.24; 95% CI = [24.56, 78.67]; p = 0.0002), V̇O₂peak (z = 3.74; 95% CI = [1.38, 4.42]; p = 0.0002), and quality of life (z = 2.66; 95% CI = [0.40, 2.63]; p = 0.008) compared to the control groups. However, the meta-analysis indicated that HIIT resulted in non-significant changes in gait speed (z = 1.43; 95% Cl = [-0.04, 0.28]; p = 0.15). CONCLUSIONS: This meta-analysis revealed that HIIT interventions in older adults positively affect cardiometabolic health parameters (6MWT, V̇O₂peak) and quality of life. Conducting HIIT as a supportive treatment component with health professionals such as physicians, physiotherapists, and nurses within the framework of a multidisciplinary team approach may contribute to improving the health of older adults. TRIAL REGISTRATION: The study was registered on the International Prospective Registry of Systematic Reviews-PROSPERO database (CRD42023481425) on November 20, 2023.