Comparative and dose-response effects of supplementary exercise training on VO

Background: Maximal oxygen uptake (VO Methods: Four databases were searched for randomized controlled trials. Bayesian network meta-analysis (NMA), Bayesian network meta-regression, and dose-response NMA were conducted. Confidence in the evidence was assessed using the Confidence in Network Meta-Analysis framework. Results: Sixty-one studies were included in the systematic review; 60 contributed to the main NMA and 31 to the dose-response NMA. Five exercise modalities were significantly superior to the active control condition, which consisted of maintaining regular sport-specific training without additional supplementary intervention: blood flow restriction training, high-intensity interval training (HIIT), intermittent hypoxic training, sprint interval training (SIT), and small-sided games (SSG). HIIT and SIT showed the most consistent overall support, although sparse subgroup findings remained exploratory. The dose-response analysis suggested that the modelled significant regions extended across the observed supplementary exercise dose ranges for HIIT, SIT, and SSG. Bayesian network meta-regression showed no clear effect modification by age, baseline VO Conclusions: Given the predominantly low to very low certainty of evidence, the findings should be interpreted cautiously. HIIT and SIT appeared to be the most consistently supported supplementary modalities for improving VO Systematic Review Registration: https://www.crd.york.ac.uk/PROSPERO/view/CRD420261360986, identifier CRD420261360986.