Effects of a 4-week high-intensity interval training on pacing during 5-km running trial
Question
Does 4 weeks of running HIIT alter pacing strategy during a 5-km time trial, and does it improve physiological determinants of endurance performance in recreational runners?
Summary
In recreational male 5-km runners, adding two weekly supervised running HIIT sessions for 4 weeks improved running economy and peak treadmill speed but did not significantly change VO2max, OBLA, 5-km time-trial performance, or pacing pattern compared with maintaining regular training.
Methodology
- Male recreational long-distance runners with recent 5-km race experience.
- 16 participants.
- Running.
- Work intervals: 50% of individual Tlim at vVO2max.
- Recovery: Equal-duration active recovery at 60% vVO2max.
- Intensity: vVO2max work intervals.
- Warm-up plus five work/recovery pairs.
- 2 sessions/week.
- 4 weeks.
- Randomized controlled 4-week training study
- Running economy, Peak treadmill speed, VO2max, and 5-km pacing were tracked.
Outcomes
Running economy
Running economy improved more in HIIT than control.
Between-group percent-change comparison p=0.012.
Peak speed
Peak treadmill speed improved more in HIIT than control.
Between-group percent-change comparison p=0.019.
VO2max
VO2max did not differ significantly between groups after training.
p=0.495.
5-km pacing
5-km pacing, time, HR, and RPE did not show significant between-group changes.
Reported p>0.05 for 5-km outcomes.
Insights
- A short two-day-per-week running HIIT block may improve economy and peak speed.
- Do not infer 5-km pacing or time-trial improvement from this 4-week protocol.
Limitations
- Small sample
- Men only
- Recreational runners only
- Short 4-week duration
- Individual time trial rather than competitive race
Safety
- No adverse events reported in the article.