# Sprint interval training (SIT) is an effective method to maintain cardiorespiratory fitness (CRF) and glucose homeostasis in Scottish adolescents

PMID: 26681833
Journal: Biology of sport
Published: 2015 Nov
Authors: Martin R, Buchan DS, Baker JS, Young J, Sculthorpe N, Grace FM

## Question

Can school-based sprint interval training maintain cardiorespiratory fitness and glucose homeostasis better than standard physical education in adolescents?

## Summary

In Scottish adolescents, replacing standard physical education with seven weeks of school-based running sprint intervals helped maintain cardiorespiratory fitness and glucose-insulin markers after summer vacation, while the standard PE group worsened. Attendance was a challenge in the SIT group.

## Population

- Apparently healthy Scottish adolescents in school PE classes
- Sample size: 43
- Age: About 16.8-16.9 years
- Sex: Not clearly extracted from NXML text
- Fitness level: High-fit adolescent cohort
- Health status: Apparently healthy and PAR-Q screened

## Methodology

- School-based randomized controlled quasi-experimental intervention
- 7 weeks
- School physical education classes and gym
- Randomized and controlled study design.

## Protocol

- School-based SIT.
- Modality: 20 m shuttle running sprints.
- Work intervals: 30 seconds.
- Recovery: 30 seconds passive recovery.
- Sets or repetitions: 4-6 sprints per session.
- Intensity: Average achieved 179 +/- 1.9 bpm, about 87% HRmax.
- Session duration: Brief SIT block after 10 minutes warm-up/stretching.
- Frequency: 3 sessions per week.
- Program length: 7 weeks.
- Progression: 4 sprints in weeks 1-2, 5 in weeks 3-4, 6 in weeks 5-7.
- Standard physical education.
- Modality: Standard school PE curriculum.
- Intensity: Standard PE.
- Session duration: 60 minutes.
- Frequency: 3 sessions per week.
- Program length: 7 weeks.
- Progression: National curriculum PE.

## Outcomes

### CRF
Status: improved
SIT maintained or trended upward for CRF while standard PE decreased.

Group-by-time p<0.01, ES=0.93; SIT trend p=0.06; SPE decreased p<0.01.

### Glucose
Status: improved
Fasted glucose remained more stable with SIT while standard PE increased.

SPE increased p<0.01; post-group difference p<0.05.

### Insulin
Status: improved
Insulin trended downward in SIT and increased in standard PE.

SIT p=0.08 trend; SPE p=0.01; post between-group p<0.01.

### Adherence
Status: worse/safety concern
SIT had lower adherence than standard PE.

Six of 26 SIT participants failed the 80% attendance requirement; SPE completion was 23 of 23.

## Practical Insights

- Brief school-based 30:30 running SIT can be time efficient but may face attendance challenges.
- Simple progression by sprint count is easy to operationalize.
- Adolescent sprint programs should be supervised and screened.

## Limitations

- Short seven-week intervention.
- High-fit adolescent cohort limits generalizability.
- No objective physical activity measure.
- Food diary under-reporting risk.
- No pre-vacation dietary data.
- Attendance attrition in SIT.

## Safety And Adherence

- No adverse events were explicitly reported in the extracted text.
- Participants were PAR-Q screened and heart rate was monitored.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/26681833/) (pubmed)
- [DOI](https://doi.org/10.5604/20831862.1173644) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4672162/) (full text)

## Agent Guidance

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