# Effort intensification and restoration in short-term HIIT predict strategic control in complex tasks

PMID: 41162584
Journal: Scientific reports
Published: 2025 Oct 29
Authors: Zhao Y, Qin C, Zhang Y, Shi Y, Wang F

## Question

How do short-term HIIT exercise duration and interval duration patterns relate to inhibitory function and weighted reaction time in college students?

## Summary

In college sports students, four acute 24-minute treadmill HIIT formats with different work and recovery durations were associated with immediate changes in Flanker-task reaction-time measures and inhibitory-function metrics. The paper suggests interval pattern and exercise intensity influenced cognitive responses, but the study used short-term surrogate cognitive outcomes and complex modeling rather than practical fitness outcomes.

## Population

- Moderately active college sports students
- Sample size: 85
- Age: Group means about 20.4-21.6 years
- Sex: 47 males and 38 females
- Fitness level: Moderate physical activity
- Health status: Screened free of cardiovascular, respiratory, knee-joint, and mental-illness history

## Methodology

- Randomized four-group acute exercise experiment
- Single 24-minute HIIT session plus immediate cognitive testing
- Laboratory treadmill and computer-based Flanker testing
- Randomized and controlled study design.

## Protocol

- Short-term HIIT.
- Modality: Treadmill.
- Work intervals: 30 s or 60 s at at least 85% HRmax.
- Recovery: 30 s, 60 s, or 120 s slow walking.
- Sets or repetitions: 8-24 intervals depending on protocol.
- Intensity: At least 85% HRmax.
- Session duration: 24 min interval block.
- Program length: Single session.
- Progression: No progression.
- Alternative HIIT interval patterns.
- Modality: Treadmill.
- Work intervals: 30 s or 60 s.
- Recovery: 30 s, 60 s, or 120 s.
- Sets or repetitions: HIIT1 24, HIIT2 16, HIIT3 12, HIIT4 8 intervals.
- Intensity: At least 85% HRmax during work.
- Session duration: 24 min interval block.
- Program length: Single session.
- Progression: No progression.

## Outcomes

### WRT base
Status: improved
Weighted reaction time in baseline-condition comparisons declined after exercise.

Largest decline was 14.8% in HIIT3 males and 13.9% in HIIT2 females, both p<0.001.

### WRT no
Status: mixed
Incongruent-task WRT was the strongest modeled factor for IF_delta.

Variance decomposition: WRT_no 49.96% pretest and 82% posttest.

### HIIT type
Status: mixed
Interval pattern influenced cognitive-response magnitude, with gender differences.

HR differed by HIIT type p<0.001; IF_delta group p values in Table 1 were not significant.

### Cognition
Status: improved
Authors concluded all four HIIT types improved cognitive function immediately after exercise.

Narrative conclusion; effects varied by task and model.

## Practical Insights

- Use cognitive claims carefully: this is immediate Flanker-task performance, not durable executive function.
- Short work and recovery choices may change acute mental responses.

## Limitations

- Acute only
- Surrogate cognitive outcomes
- No long-term training arm
- Reasons for dropout not described
- Moderately active student sample

## Safety And Adherence

- No adverse events reported in extracted text.
- Seven of 92 initial participants did not complete the whole test; reasons not reported.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/41162584/) (pubmed)
- [DOI](https://doi.org/10.1038/s41598-025-21789-7) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12572404/) (full text)

## Agent Guidance

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