Markers for Routine Assessment of Fatigue and Recovery in Male and Female Team Sport Athletes during High-Intensity Interval Training
Question
Which routine fatigue and recovery markers reflect repeated-sprint ability changes after a short intensified HIIT block in team-sport athletes?
Summary
In trained team-sport athletes, an intense six-day HIIT block produced measurable fatigue, soreness, and some performance decrements, but no single routine marker accurately tracked repeated-sprint recovery.
Methodology
- Healthy well-trained male and female team-sport athletes.
- 22 participants.
- Running.
- Work intervals: Mixed: 4 min, 2 min, 30 s shuttle, and 5 s all-out sprint intervals.
- Recovery: Mixed: 25 s to 3 min plus set recoveries.
- Intensity: 80-90% VIFT or all-out.
- Average 35 min.
- 11 sessions over 6 days.
- 6 days.
- Repeated-measures training-load and recovery study
- Repeated-sprint ability, and Recovery markers were tracked.
Outcomes
RSA
Repeated-sprint ability decreased after HIIT and recovered by 72 h.
5.02 to 4.84 m/s post-HIIT, p=0.001; 4.97 m/s after 72 h.
Fatigue markers
CMJ, MRJ, CK, and DOMS changed with fatigue/recovery, while sprint time and some contractile measures remained impaired at 72 h.
Marker accuracy
No single marker accurately tracked RSA changes.
Multiple regression showed no useful correlations.
Insights
- Recovery status after hard HIIT blocks should be judged from multiple individual markers.
- Athlete overload microcycles are not appropriate templates for general fitness users.
Limitations
- No control group
- Athlete-only cohort
- Selected marker battery
- Generalizability to other athlete levels uncertain
Safety
- No conventional adverse events or injuries were reported.
- Expected fatigue responses included increased DOMS and creatine kinase after HIIT.
- Participants were screened by health exam and normal ECG, sessions were supervised, and no in-study dropout was reported.