PMID 41622262

Research
All papers

High-intensity interval training improves the reactive strength index and motor ability of youth football players

Kızılca S, Kahraman MZ, Okut S, Arslan E, Bilici ÖF, Çelik İ, İşlen T, Altıntaş S, Bilici MF

Question

Does a 4-week running-based HIIT block improve reactive strength index and motor abilities in 11-13-year-old male football players compared with regular football training alone?

Summary

In 20 male youth football players aged 11-13, adding an 8-minute running HIIT segment three times per week for 4 weeks improved within-group performance measures and group-by-time interactions for RSI, sprinting, back strength, agility, and countermovement jump. Post-test between-group differences were not significant, and all participants completed the protocol without adverse events.

Methodology

  • Male youth football players aged 11-13 years
  • 20 participants.
  • Running.
  • Work intervals: 15 seconds.
  • Recovery: 30 seconds; 3 minutes between sets.
  • Intensity: 80-90% target HR progression.
  • 8-minute HIIT block.
  • 3 days/week.
  • 4 weeks.
  • Randomized pretest-posttest controlled trial
  • Reactive strength index, Sprint performance, Back strength, and Agility and jump were tracked.

Outcomes

RSI

RSI improved with significant group-by-time interaction favoring HIIT.

p<0.05; large effect sizes reported

Improved

sprint and COD

Sprint and change-of-direction outcomes improved within the HIIT group and had significant group-by-time interactions.

p<0.05; partial eta squared 0.20-0.30 for interactions

Improved

between-group post-test

Despite favorable changes, post-test between-group comparisons were not statistically significant.

Post-test between-group comparisons not significant

No clear change

safety

No adverse events, injuries, or unintended effects occurred.

No clear change

Insights

  • A short 8-minute HIIT block can replace, not add to, lower-intensity practice work to manage total load.
  • For performance goals, 15-second efforts with 30-second recoveries are useful and easy to express in an app.
  • Youth-related content must keep supervision and population limits explicit.

Limitations

  • Small sample
  • Male youth football players only
  • No follow-up
  • Between-group post-test differences not significant
  • No quantitative total-load monitoring beyond duration

Safety

  • No adverse events, injuries, or unintended effects were observed in either group.
  • All sessions included standardized warm-up and cooldown routines under certified supervision.