Effect of Linear Sprints and Change-of-Direction Training Versus Small-Sided Soccer Games on Physical Performance in Highly Trained Young Female Soccer Players: A Randomized Cross-Over Study

Background: This study aimed to compare the effects of linear sprint training with changes of direction (LSCD) versus small-sided games (SSSG) on physical performance, agility, and soccer-specific skills in young elite female players. Methods: In a randomized crossover study, 27 players aged 15 to 17 were divided into two groups (G1 = 14, G2 = 13). After a two-week baseline period, each group completed a four-week training mesocycle (three sessions per week) consisting of either LSCD or SSG. After a two-week washout period, participants switched interventions and completed the alternate four-week mesocycle. Performance assessments were conducted before and after each mesocycle to evaluate training effects. Results: Both types of training improved physical performance, with different magnitudes. LSCD induced larger gains in sprint speed (5, 10, 20 m; <i>p</i> < 0.05), agility without the ball (<i>t</i>-test; <i>p</i> = 0.05), and explosive power (countermovement jump, repeated jumps over 15 s; <i>p</i> = 0.02 and <i>p</i> = 0.004). In contrast, SSSG led to larger improvements in aerobic endurance (Yo-Yo IR1 test; <i>p</i> = 0.03) and agility with the ball (<i>t</i>-test with ball; <i>p</i> = 0.05). No transfer effect between cycles was observed. Conclusions: In young elite female players, LSCD training was more effective in improving speed, agility, and power, while SSSG was more effective for aerobic endurance and ball agility.