# The effects of 8 weeks of sprint interval training on repeated sprinting and specialized ability in college volleyball players

PMID: 40668810
Journal: PloS one
Published: 2025
Authors: Wei C, An J, Zhou L

## Question

Does sprint interval training improve repeated sprint ability, aerobic capacity, agility, and volleyball-specific jumping more than high-intensity interval training in collegiate volleyball players?

## Summary

In 28 male collegiate volleyball players, 8 weeks of twice-weekly sprint interval training improved aerobic capacity, repeated sprint performance, agility, and jumping measures more than a high-intensity shuttle-running comparator. The study is useful for sport-specific sprint programming but is limited by the small athlete-only sample, no usual-training control, and an internal inconsistency in the methods text about the intervention duration.

## Population

- Male collegiate volleyball players
- Sample size: 28
- Age: SIT 19.8 +/- 2.67 years; HIIT 20.7 +/- 1.4 years
- Sex: Male
- Fitness level: Provincial-level collegiate volleyball players with at least 5 years of experience
- Health status: Apparently healthy after medical screening

## Methodology

- Randomized controlled training study
- 8 weeks
- College volleyball training context
- Randomized and controlled study design.

## Protocol

- SIT.
- Modality: Running sprint intervals.
- Work intervals: 30 m all-out sprint.
- Recovery: About 30 seconds between repetitions and about 2 minutes between series.
- Sets or repetitions: Six repetitions per series; 2-3 series depending on stage.
- Intensity: All-out sprint effort.
- Session duration: Not clearly reported; included about 15 min warm-up plus sprint series.
- Frequency: 2 sessions/week.
- Program length: 8 weeks.
- Progression: Tabled stages across weeks 1-2, 3-5, and 6-8 varied series count.
- HIIT.
- Modality: Shuttle running.
- Work intervals: 20 seconds.
- Recovery: 30 seconds between repetitions and about 2 minutes between series in the tabled protocol.
- Sets or repetitions: Six repetitions per series; 2-3 series depending on stage.
- Intensity: About 90% to 95% HRmax.
- Session duration: Not clearly reported beyond warm-up and interval structure.
- Frequency: 2 sessions/week.
- Program length: 8 weeks.
- Progression: Staged series progression similar to the SIT group.

## Outcomes

### VO2max
Status: improved
Both groups improved, with greater improvement in the SIT group.

SIT 46.93 +/- 4.25 to 50.90 +/- 4.17 ml/kg/min; HIIT 45.55 +/- 5.34 to 47.53 +/- 5.33 ml/kg/min; time and interaction p<0.001.

### vVO2max
Status: improved
Both groups improved, with a larger gain after SIT.

SIT 14.53 +/- 1.61 to 17.03 +/- 1.15 km/h; HIIT 15.05 +/- 1.41 to 15.89 +/- 1.23 km/h; interaction p<0.001.

### Repeated sprints
Status: improved
Initial sprint time and total sprint time improved in both groups, with larger effect sizes in SIT.

Initial sprint SIT d=1.060 vs HIIT d=0.581; total sprint SIT d=1.164 vs HIIT d=0.678.

### Agility
Status: improved
Modified agility T-test improved more in SIT than HIIT.

SIT 7.85 +/- 1.04 to 6.87 +/- 0.71 s; HIIT 7.68 +/- 1.02 to 7.25 +/- 0.77 s; interaction p=0.041.

### Jump performance
Status: improved
Countermovement jump and spike jump improved in both groups, with greater gains after SIT.

CMVJ interaction p=0.003; SPJ interaction p=0.003.

### VT2
Status: no clear change
The group-by-time difference for VT2 was not significant.

No significant between-group difference reported for VT2.

## Practical Insights

- All-out sprint intervals may be useful for trained team-sport athletes when performance outcomes are the target.
- The sport-specific translation depends on sprint space, warm-up quality, and athlete readiness.
- Do not translate the results as general-population safety evidence for all-out sprinting.

## Limitations

- Small sample
- Male athlete-only population
- No usual-training control group
- Assessors were not blinded
- Training load and biochemical markers were not monitored
- No long-term retention, recovery, or injury outcomes
- Internal inconsistency in the methods text about four versus eight weeks

## Safety And Adherence

- Participants were medically screened.
- All participants completed the study.
- Adverse events or training injuries were not explicitly reported.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/40668810/) (pubmed)
- [DOI](https://doi.org/10.1371/journal.pone.0327561) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12266437/) (full text)

## Agent Guidance

Preserve the paper-level scope of this note. Do not generalize beyond the population, protocol, measured outcomes, and limitations above.