PMID 41018890

Research
All papers

Effects of 4-week velocity-based HIIT on athletic performance in youth soccer players

Koç M, Adıgüzel NS, Engin H, Öztürk B, Canli U, Karaçam A, Orhan BE, Prieto-González P, Bartik P, Alghemlas S, Isip M, Sagat P

Question

Does adding individualized velocity-based HIIT to regular soccer training improve sprint speed, change of direction, intermittent running performance, and estimated aerobic fitness in youth soccer players over four weeks?

Summary

A very small randomized study in youth male soccer players found that adding four weeks of velocity-based HIIT to normal soccer training improved maximal sprint speed, change of direction, final intermittent-fitness-test speed, and estimated VO2max more than regular soccer training alone. The study was underpowered, short, and limited to one male team.

Methodology

  • Youth male semi-professional soccer players from one club.
  • 14 participants.
  • Running intervals prescribed from individual 30-15 Intermittent Fitness Test velocity.
  • Work intervals: Each repetition used 20 seconds of exertion followed by 10-20 seconds of rest.
  • Recovery: Each repetition used 20 seconds of exertion followed by 10-20 seconds of rest.
  • Intensity: Intervals were prescribed at 85-90% of VIFT and progressed every 2 weeks.
  • Each vHIIT session consisted of three sets of seven repetitions, with 3 minutes of rest between sets.
  • 2 vHIIT sessions per week in addition to regular team training.
  • 4 weeks.
  • Parallel-group randomized controlled trial testing velocity-based HIIT added to regular soccer training.
  • Maximal sprint speed, Change of direction, Intermittent running fitness, and Estimated aerobic fitness were tracked.

Outcomes

Velocity-based HIIT effects

All four main outcomes showed significant group-by-time interactions favoring velocity-based HIIT.

Mixed

Maximal sprint speed

Maximal sprint speed improved about +3.79% in the vHIIT group versus +0.40% in control.

Improved

Change-of-direction time

Change-of-direction time improved about -2.21% in the vHIIT group, while control slightly worsened by about +0.40%.

Improved

Intermittent running fitness

VIFT improved about +5.05% in the vHIIT group versus +1.15% in control.

Improved

Estimated VO2max

Estimated VO2max improved about +4.76% in the vHIIT group versus +0.95% in control.

Improved

Insights

  • Velocity-based HIIT can individualize running speed targets using 30-15 Intermittent Fitness Test performance.
  • Short 20-second running intervals at 85-90% VIFT may improve soccer-relevant speed and intermittent fitness over a short block in trained players.
  • In app settings, speed-based prescription requires either reliable field testing or a practical substitute for VIFT.

Limitations

  • Very small final sample of 14 players, with only 7 per group.
  • The authors' power analysis indicated that 34 participants were required, so the study was underpowered.
  • Short 4-week intervention.
  • Male-only, single-club soccer sample.
  • Training load was not fully matched between groups because vHIIT was added to regular training.
  • VO2max was estimated rather than directly measured.
  • Assessors were not blinded.

Safety

  • Four initial volunteers reportedly dropped out due to injury and two were excluded for incomplete data, but the extracted article text did not make clear whether those injuries were caused by the intervention. No detailed intervention adverse-event reporting was identified.