Effects of Small-Sided Games and Repeated Sprint Training in Young Soccer Players

High-intensity intermittent actions, such as accelerations, change-of-direction movements, jumps, and repeated sprints, are critical determinants of competitive performance in soccer. To optimize these physical attributes, coaches commonly utilize Small-Sided Games (SSG) and Repeated Sprint Training (RST). However, comparative evidence regarding the specific adaptations induced by these two distinct conditioning strategies alongside regular soccer practice remains crucial for athletic peroidization.

This 6-week randomized controlled trial evaluated 24 young male soccer players randomly allocated into three parallel arms (n=8 per group): SSGG, RSTG, and a Control Group (CG).

Training Protocols:

• SSGG Protocol: Performed a "4 vs. 4 Transition Possession" format on two adjacent zones 3 days per week (Mondays, Wednesdays, Fridays) after the technical section of regular practice. Training volume progressed from 3 sets x 3 min (weeks 1-2) to 4 sets x 3 min (weeks 3-4) and 4 sets x 4 min (weeks 5-6), with 2-minute passive recovery between sets.
• RSTG Protocol: Performed 20-meter linear maximal sprints with 20 seconds of active recovery (slow walking) between repetitions and 3-4 minutes of passive rest between sets. Volume progressed from 2 sets x 6 reps (weeks 1-2) to 2 sets x 8 reps (weeks 3-4) and 3 sets x 6 reps (weeks 5-6).
• Control Group: Maintained standard soccer training sessions planned by the head coach, without any additional physical conditioning intervention.

Assessments:

Body composition parameters were evaluated via bioelectrical impedance analysis (Tanita BC-418 MA). Laboratory testing included the 30-second Wingate Anaerobic Test (Monark 834 E) with a load equal to 7.5% of body weight to assess peak and mean anaerobic power. Field testing included 10m and 20m sprint times using electronic photocells (Smart Speed Lite), change-of-direction performance via the Illinois Agility Test, and lower-body explosive power via the Countermovement Jump test (Smart Jump mat).

Inclusion criteria

• Active male soccer players competing in the Regional Amateur League (BAL)
• Age between 16 and 20 years
• Voluntary participation with signed informed consent (and parental consent for minors)
• No history of severe musculoskeletal injuries or orthopedic surgeries in the lower extremities within the past 6 months
• Regular participation in team soccer practices

Exclusion criteria

• Missing more than 10% of the scheduled training sessions during the 6-week intervention
• Occurrence of any acute musculoskeletal injury or illness preventing full participation in tests or training
• Simultaneous participation in external structured strength or conditioning programs outside the study protocol
• Failure to complete all pre- or post-intervention performance tests