Comparative of Different Interval Training Methods on Athletes' Oxygen Uptake: A Systematic Review and Meta-analysis

Background This systematic review aimed to 1) investigate the comparative efficacy of high-intensity interval training (HIIT), sprint interval training (SIT), and repetitive sprint training (RST) on athletes' oxygen uptake, 2) examine the effects of program protocols for each training method on enhancing oxygen uptake, 3) provide evidence-based insights to inform future research. Methods Data sources, Web of Science, PubMed, Scopus, PsycINFO, SPORTDiscus, CINAHL, Medline, and Embase. Eligibility criteria, between-groups controlled experimental studies (2000–present) that investigated the effect of improving athletes' oxygen uptake levels by RST, HIIT, and SIT. Study selection and analysis, sensitivity, and indirectness in the network were assessed by two independent investigators. A frequentist network meta-analysis was performed to examine pre-post intervention differences in oxygen uptake between groups. Results 32 studies (n=768) with 42 comparisons were included in the network. Compared with MICT, RST significantly increased the oxygen uptake (SMD: 0.87, 95% CI 0.44 to 1.33), whereas HIIT (SMD: 0.81, 95% CI 0.50 to 1.11), and SIT (SMD: 0.43, 95% CI 0.16 to 0.70) significantly elevated the oxygen uptake in athletes. Compared with CON, HIIT (SMD: 0.87, 95% CI 0.39 to 1.90), and RST (SMD: 0.71, 95% CI 0.40 to 1.01). Ranking on the basis of the P-score was consistent with that derived from the SUCRA: RST > HIIT > SIT > CON > MICT. In SIT, the total number of repetitions per session (β: -0.01, 95% CI -0.03 to -0.01), and interval duration (β: -0.01, 95% CI -0.0016 to -0.0002) showed a significant dose‒response relationship. Conclusions A 6-week running-based HIIT program with work‒recovery intervals of 2‒3 days per week improved athletes' oxygen uptake levels. With work‒recovery intervals of 30 seconds and 60‒90 seconds, respectively, 3 days/week, SIT with less volume may prove more efficacious. Systematic review registration PROSPERO CRD42023435021.