Abstract Xiao, Y, Li, J, Deng, Z, and Gao, W. Effects of high-intensity interval training versus sprint interval training on factors related to endurance performance: A systematic review and meta-analysis. J Strength Cond Res 40(3): 344–355, 2026—This meta-analysis aimed to compare the long-term effects (≥2 weeks) of high-intensity interval training (HIIT) and sprint interval training (SIT) on endurance performance-related outcomes, including maximal oxygen uptake (V̇ o 2 max), endurance performance, maximal aerobic power/velocity (MAP/MAV), lactate threshold, and running economy. A systematic literature search was conducted using the keywords “high-intensity interval training” and “sprint interval training” in the Web of Science, PubMed, and SPORTDiscus databases. A random-effects model was applied, with standardized mean difference (SMD) calculated for each outcome. Subgroup and regression analyses were performed to examine potential moderating factors. Twelve randomized crossover trials involving 460 subjects were included. High-intensity interval training significantly outperformed SIT in improving V̇ o 2 max (SMD = 0.56, 95% confidence interval CI: 0.23–0.88; p 4 minutes, >8 weeks). Although most outcomes were of low or very low quality (except MAP/MAV), these findings suggest that athletes and coaches may incorporate 3–6 intervals of 4–5 minutes at 80–95% MAV, 2–3 sessions per week, to enhance aerobic capacity.
Xiao et al. (Wed,) studied this question.