# Recovery time variation during sprint interval training impacts amateur soccer players adaptations - a pilot study

PMID: 37077796
Journal: Biology of sport
Published: 2023 Apr
Authors: Diker G, Darendeli A, Chamari K, Dellal A, Müniroğlu S, Ön S, Özkamçı H

## Question

How does recovery duration during sprint interval training affect aerobic and repeated-sprint adaptations in amateur soccer players?

## Summary

In amateur male soccer players, adding six weeks of running sprint interval training to regular soccer training improved intermittent-running and VO2max measures. Longer 150-second recovery between 30-second all-out sprints appeared more favorable for repeated-sprint performance than 30-second recovery.

## Population

- Male amateur soccer players with at least 5 years of soccer training background.
- Sample size: 23
- Age: About 21.4 +/- 1.1 years
- Sex: Male
- Fitness level: Amateur soccer players
- Health status: Apparently healthy athletes

## Methodology

- Randomized controlled pilot intervention
- 6-week intervention after 3-week preparation period
- Outdoor soccer training setting
- Randomized and controlled study design.

## Protocol

- SIT150.
- Modality: Running all-out sprints.
- Work intervals: 30 seconds.
- Recovery: 150 seconds.
- Sets or repetitions: 6-10 repetitions.
- Intensity: All-out.
- Session duration: Sprint block duration increased with repetitions; warm-up included 5 min jogging, 3 min dynamic stretching, and 7 min drills.
- Frequency: 2 sprint sessions per week plus regular soccer training.
- Program length: 6 weeks.
- Progression: 6 reps in weeks 1-2, 8 reps in weeks 3-4, and 10 reps in weeks 5-6.
- SIT30 and routine soccer control.
- Modality: Running all-out sprints or routine soccer training.
- Work intervals: 30 seconds for SIT30.
- Recovery: 30 seconds for SIT30.
- Sets or repetitions: 6-10 repetitions for SIT30.
- Intensity: All-out for SIT30; routine soccer intensity varied.
- Session duration: SIT30 sprint block shorter than SIT150; control performed routine training and match only.
- Frequency: 2 sprint sessions per week plus routine training for SIT30; routine soccer training and weekly match for control.
- Program length: 6 weeks.
- Progression: Same repetition progression for SIT30.

## Outcomes

### Yo-Yo IRT1
Status: improved
All groups improved, with the largest gain in the 150-second recovery group.

SIT150 +43%, p=0.001, d=1.48; SIT30 +23%, p=0.002, d=0.76; control +20%, p=0.013, d=0.57.

### Yo-Yo IRT2
Status: improved
Both sprint interval groups improved Yo-Yo IRT2, with larger relative gain in SIT150.

SIT150 +32.8%, p=0.008, d=1.25; SIT30 +26.2%, p=0.018, d=1.28.

### VO2max
Status: improved
VO2max improved in all groups, including the routine soccer control group.

SIT150 +18%, p=0.010, d=1.56; SIT30 +19.1%, p=0.001, d=1.97; control +13.4%, p=0.002, d=0.75.

### Repeated sprint
Status: mixed
Repeated-sprint test variables did not show group-level improvements, and SIT30 worsened in best and total sprint times.

No time-by-group interaction; SIT30 RSTbest worsened 3.5%, p=0.029, and RSTtotal worsened 2.5%, p=0.038.

## Practical Insights

- For all-out 30-second running sprints in soccer players, longer recovery may preserve repeated-sprint quality better than short 30-second recovery.
- Routine soccer training also improved VO2max, so added SIT effects should be interpreted against strong background training.
- This is athlete-specific and not a general beginner HIIT prescription.

## Limitations

- Pilot study with small groups.
- Control training was not volume-matched.
- Training workload was not fully controlled or monitored.
- Treadmill VO2max protocol limitations were acknowledged by the authors.
- Male amateur soccer players only.

## Safety And Adherence

- One participant in the SIT30 group was injured during training and excluded from analysis; attribution to the intervention was not clearly specified.
- No other adverse-event details were reported.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/37077796/) (pubmed)
- [DOI](https://doi.org/10.5114/biolsport.2023.116008) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10108749/) (full text)

## Agent Guidance

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