PMID 40940682

Research
All papers

Effect of High-Intensity Interval Training With Varying Work-to-Rest Ratios on Specific Physical Fitness in Adolescent Taekwondo Athletes

Xu N, Xue Y, Zhang M

Question

How do two sport-specific HIIT work-to-rest ratios, 20 seconds work/10 seconds rest and 30 seconds work/10 seconds rest, affect physical fitness and taekwondo-specific performance in adolescent taekwondo athletes?

Summary

In high-level adolescent taekwondo athletes, 8 weeks of sport-specific HIIT improved repeated kicking endurance, heart-rate recovery, and some performance measures. Longer 30-second work bouts seemed better for aerobic and repeated-kicking endurance outcomes, while 20-second work bouts appeared more favorable for agility and brief kicking-speed outcomes. The sample was small and sport-specific.

Methodology

  • High-level adolescent taekwondo athletes from a Chinese sport institute team.
  • 30 participants.
  • High-intensity continuous kicking combinations using taekwondo techniques.
  • Work intervals: HIIT-20S used repeated 20-second work bouts with 10-second rests. HIIT-30S used repeated 30-second work bouts with 10-second rests. Each group completed three 2-minute rounds.
  • Recovery: HIIT-20S used repeated 20-second work bouts with 10-second rests. HIIT-30S used repeated 30-second work bouts with 10-second rests. Each group completed three 2-minute rounds.
  • Intensity: At least 85% HRmax, monitored continuously with Polar V800 heart-rate monitors.
  • Each session included a 15-minute warm-up, three 2-minute high-intensity rounds separated by 1-minute recoveries, and about 7 minutes of stretching/relaxation.
  • 3 sessions per week.
  • 8 weeks.
  • Three-arm randomized controlled trial comparing two taekwondo-specific HIIT work-rest ratios with active sport training control.
  • Cardiorespiratory fitness, Heart-rate recovery, Taekwondo-specific kicking performance, and Strength and agility were tracked.

Outcomes

VO2peak

VO2peak improved most in HIIT-30S, about +4.72%, compared with +1.96% for HIIT-20S and +0.47% for control; the time-by-group interaction was significant.

Improved

Heart-rate recovery

Heart-rate recovery improved in both HIIT groups, with HIIT-30S significantly better than control.

Improved

Repeated kicking endurance

Repeated kicking endurance improved in both HIIT groups, especially HIIT-30S: FSKTtotal increased about +5.09% in HIIT-30S, +2.00% in HIIT-20S, and +0.58% in control.

Improved

Kick decrement index

Kick decrement index improved most in HIIT-30S, about -21.73%, compared with -12.21% for HIIT-20S and -2.27% for control.

Improved

Agility

Agility improved most in HIIT-20S, with improved Illinois agility test time decreasing about -8.26% versus -4.01% for HIIT-30S and -0.85% for control.

Improved

Maximal squat strength

Maximal squat strength did not show meaningful group-differentiated improvement.

No clear change

Insights

  • Work-to-rest ratio can be matched to the target quality: 30-second bouts may favor repeated high-intensity endurance, while shorter 20-second bouts may better preserve speed and agility emphasis.
  • Sport-specific movement selection can make HIIT highly relevant to athletes but limits translation to general exercise users.
  • HIIT alone may not improve maximal strength in trained athletes; resistance training may be needed for that target.
  • Heart-rate monitoring was used to maintain high-intensity exposure across groups.

Limitations

  • Small sample size with only 10 athletes per group.
  • Athlete-only adolescent population limits generalization.
  • The protocol was highly taekwondo-specific.
  • The intervention lasted only 8 weeks.
  • The authors noted limited individualization and the need for longer or larger studies.

Safety

  • No adverse-event reporting was identified in the extracted article text.