# Effects of high-intensity interval training on executive functions and IGF-1 levels in sedentary young women: a randomized controlled trial

PMID: 40538943
Journal: Frontiers in Sports and Active Living
Published: 2025-06-04
Authors: Jimenez-Roldán MJ, Sañudo Corrales B, Carrasco Páez L

## Question

Does online HIIT, with or without an added daily-step goal, improve salivary IGF-1 and executive functions in sedentary young women compared with control?

## Summary

This randomized trial tested 12 weeks of online HIIT, HIIT plus a 10,000-steps/day physical activity goal, or control in sedentary young women. The study did not find clear group-by-time effects showing that HIIT specifically improved salivary IGF-1 or executive function. Some cognitive scores improved over time, but the pattern was not specific to the intervention groups, so practice effects or outside factors remain plausible.

## Population

- Sedentary young women.
- Sample size: 77
- Age: Mean about 22 +/- 1.1 years.
- Sex: Female.
- Fitness level: Low physical activity by IPAQ.
- Health status: Healthy university students.

## Methodology

- Three-arm randomized controlled trial with blinded assessors/data analysts and 12-week follow-up after training stopped.
- 12-week intervention plus 12-week unsupervised follow-up.
- Online group exercise sessions for sedentary university women.
- Randomized and controlled study design.

## Protocol

- Online HIIT.
- Modality: Bodyweight/cardio online HIIT.
- Work intervals: 30 s exercise.
- Recovery: 30 s rest.
- Sets or repetitions: 24-36 min main set.
- Intensity: RPE 8 progressing to 9-10 on CR10.
- Session duration: About 40 min.
- Frequency: 3 sessions/week.
- Program length: 12 weeks.
- Progression: RPE target increased every few weeks.
- Control.
- Modality: Usual routine without structured exercise.
- Frequency: Weekly check-ins.
- Program length: 12 weeks plus follow-up.

## Outcomes

### IGF-1
Status: no clear change
No statistically significant group, time, or interaction effect for salivary IGF-1.

Reported p values > .40.

### Executive function
Status: mixed
Some measures improved over time, but not with consistent group-by-time effects attributable to HIIT.

Digit Span Backward time p < .001 but interaction p = .286; Digit Span Total interaction p = .081.

## Practical Insights

- 30/30 online HIIT is implementable, but this trial does not justify strong cognition or IGF-1 claims.
- Daily activity goals may be paired with structured HIIT, but evidence here is trend-level.

## Limitations

- Attrition from 77 to 58 analyzed.
- Healthy young women only.
- Practice effects in cognitive testing.
- Surrogate biomarker outcome.
- No detailed adverse-event reporting.
- Online supervision and no objective neurobiological measures.

## Safety And Adherence

- No adverse-event details were reported.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/40538943/) (pubmed)
- [DOI](https://doi.org/10.3389/fspor.2025.1597171) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12177337/) (full text)

## Agent Guidance

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