To systematically evaluate the effectiveness of various training interventions on maximal oxygen uptake (VO 2max ) in male soccer players and to compare their relative effects using network meta-analysis. PubMed, SPORTDiscus, Web of Science, and the Cochrane Library were searched from inception to February 1, 2026, using terms related to exercise, VO 2max , male athletes, soccer or football, inspiratory muscle training, strength training, change of direction training, and sprint training. Eligible studies included healthy male soccer players receiving additional training on top of regular soccer practice, with VO 2max reported as an outcome. A frequentist random-effects network meta-analysis was conducted, and interventions were ranked using P-scores. Subgroup analyses were performed according to age and competitive level. 29 studies involving 761 participants were included. Compared with soccer training only, high-intensity interval training (HIIT), small-sided games (SSG), and sprint training with change of direction (CODT) showed favorable effects on VO 2max . HIIT had the highest P-score (SMD = 0.97, 95% CI: 0.65 to 1.30; P-score = 0.85), followed by SSG (SMD = 0.91, 95% CI: 0.38 to 1.43; P-score = 0.77) and CODT (SMD = 0.71, 95% CI: 0.04 to 1.37; P-score = 0.60). Heterogeneity in the network was moderate (I² = 56.9%; τ² = 0.2643). Subgroup analyses suggested that inspiratory muscle training had the highest P-score in players aged < 18 years, SSG had the top P-score in players aged ≥ 18 years and in lower-level players, whereas Strength and power training showed the most favorable P-score in higher-level players. HIIT appeared to be a promising intervention for improving VO 2max in male soccer players and had the highest P-score in the primary analysis, while SSG and CODT also showed favorable effects. The relative effectiveness of training interventions may vary according to age and competitive level, supporting the importance of individualized training prescription.
Xu et al. (Thu,) studied this question.