Effects of integrating intermittent training, interval training, and small-sided games on aerobic capacity in youth soccer players using a 3:1 periodized micro-cycle

: This study investigated the effectiveness of integrating intermittent training, interval training, and small-sided games (SSGs) within a structured 3:1 micro-cycle to enhance aerobic capacity (VO2max) in young soccer players. Over 16 weeks, 30 semi-professional U16 and U19 players completed a periodized training program involving aerobic, strength, speed, and tactical components. VO2max was assessed pre- and post-intervention using Yo-Yo test. One-way ANOVA conducted on post-intervention VO₂max improvement revealed a significant between-group difference (F(1, 28) = 5.47, p = 0.027, η2 = 0.07), with U19 players demonstrating greater improvements (M = 29.49, SD = 12.39) compared with U16 players (M = 22.35, SD = 10.27). A mixed-design ANOVA showed a significant main effect of group across time (F(1, 27) = 131.19, p < 0.001, η2p = 0.83), indicating substantially higher overall aerobic gains in the U19 group. The group × time interaction did not reach statistical significance (p = 0.065), although a trend-level effect suggested a potential influence of age-related factors on training response. Correlation analyses indicated that lateral-position players exhibited stronger associations with VO2max improvement (U16: r = 0.78; U19: r = 0.94) compared with central-position players (U16: r = 0.21; U19: r = 0.17). These outcomes show the impact of integrated training models and mention the importance of age- and position specific conditioning in youth soccer.