Is Low-Volume High-Intensity Interval Training a Time-Efficient Strategy to Improve Cardiometabolic Health and Body Composition? A Meta-Analysis

Abstract

The present meta-analysis aimed to assess the effects of low-volume high-intensity interval training (LV-HIIT; i.e., ≤5 min high-intensity exercise within a ≤15-min session) on cardiometabolic health and body composition. A systematic search was performed in accordance with PRISMA guidelines to assess the effect of LV-HIIT on cardiometabolic health and body composition. Twenty-one studies (moderate to high quality) with a total of 849 participants were included in this meta-analysis. LV-HIIT increased cardiorespiratory fitness (CRF, SMD=1.19 [0.87, 1.50]) while lowering systolic blood pressure (SMD=-1.44 [-1.68, -1.20]), diastolic blood pressure (SMD=-1.51 [-1.75, -1.27]), mean arterial pressure (SMD=-1.55 [-1.80, -1.30]), MetS z-score (SMD=-0.76 [-1.02, -0.49]), fat mass (kg) (SMD=-0.22 [-0.44, 0.00]), fat mass (%) (SMD=-0.22 [-0.41, -0.02]), and waist circumference (SMD= -0.53 [-0.75, -0.31]) compared to untrained control (CONTROL). Despite a total time-commitment of LV-HIIT of only 14-47% and 45-94% compared to moderate-intensity continuous training and HV-HIIT, respectively, there were no statistically significant differences observed for any outcomes in comparisons between LV-HIIT and moderate-intensity continuous training (MICT) or high-volume HIIT. Significant inverse dose–responses were observed between the change in CRF with LV-HIIT and sprint repetitions (β=−0.52 [-0.76, -0.28]), high-intensity duration (β=−0.21 [-0.39, -0.02]), and total duration (β=−0.19 [-0.36, -0.02]), while higher intensity significantly improved CRF gains. LV-HIIT can improve cardiometabolic health and body composition and represent a time-efficient alternative to MICT and HV-HIIT. Performing LV-HIIT at a higher intensity drives higher CRF gains. More repetitions, longer time at high-intensity, and total session duration did not augment gains in CRF.