# Effects of linear and change of direction high-intensity interval training on physical performance of elite female soccer players

PMID: 39416496
Journal: Biology of sport
Published: 2024 Oct
Authors: Stanković M, Trajković N, Mačak D, Đorđević D, Lazić A, Milanović Z

## Question

Do linear and change-of-direction HIIT produce different physical-performance adaptations in elite female soccer players?

## Summary

In elite female soccer players, 6 weeks of linear or change-of-direction running HIIT improved sprinting, agility, jumping, repeated-sprint, and 30-15 IFT outcomes. The change-of-direction version was not clearly superior overall.

## Population

- Elite female soccer players training at the highest level.
- Sample size: 30
- Age: 19.6 +/- 4.6 years
- Sex: female only
- Fitness level: elite soccer players with more than 5 sessions/week
- Health status: screened for disease, rehabilitation status, recent distortion, and ACL surgery

## Methodology

- randomized two-group training intervention
- 6 weeks
- preseason soccer training on natural grass
- Randomized and controlled study design.

## Protocol

- HIIT with change of direction.
- Modality: running.
- Work intervals: 15, 20, or 25 s.
- Recovery: equal passive recovery at 0% VIFT.
- Sets or repetitions: 8 reps x 3 series.
- Intensity: 100% VIFT, distance reduced 7% for COD cost.
- Session duration: about 18, 22, or 26 min for weeks 1-2, 3-4, and 5-6 after 17 min warm-up.
- Frequency: 2 sessions/week.
- Program length: 6 weeks.
- Progression: 15 s intervals in weeks 1-2, 20 s in weeks 3-4, 25 s in weeks 5-6; VIFT updated every third week.
- Linear HIIT.
- Modality: running.
- Work intervals: 15, 20, or 25 s.
- Recovery: equal passive recovery.
- Sets or repetitions: 8 reps x 3 series.
- Intensity: 100% VIFT constant-pace linear running.
- Session duration: about 18, 22, or 26 min after 17 min warm-up.
- Frequency: 2 sessions/week.
- Program length: 6 weeks.
- Progression: same interval-duration progression and VIFT updates.

## Outcomes

### Performance tests
Status: improved
Both linear and COD groups improved most measured performance outcomes.

Both groups improved all physical performance measurements except RSAbest in HIITLIN (reported nonsignificant p around 0.4-0.45)

### VO2max
Status: improved
Both groups improved 30-15 IFT-derived VO2max and VIFT.

VO2max +3.9% HIITLIN and +7.4% HIITCOD; VIFT +4.0% HIITLIN and +7.8% HIITCOD

### Group difference
Status: no clear change
The COD version was not superior to linear HIIT across outcomes.

Authors report no group x time superiority for HIITCOD

## Practical Insights

- Work duration progression from 15 to 25 s can raise dose while preserving 1:1 work/rest.
- COD intervals increase sport specificity but should reduce distance for turning cost.
- Elite athlete findings should not be used as a direct beginner prescription.

## Limitations

- No non-HIIT control group.
- Small elite female sample.
- Wide age range from 16 to 26 years.
- Adverse events and dropout were not explicitly reported in the NXML.

## Safety And Adherence

- The article reported injury/disease exclusions and supervision but did not explicitly report adverse events or dropout in the extracted NXML.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/39416496/) (pubmed)
- [DOI](https://doi.org/10.5114/biolsport.2024.134761) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11475003/) (full text)

## Agent Guidance

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