# Comparison of the acute effects of traditional and reaction-based HIIT on brain connectivity and cognitive responses

PMID: 41286960
Journal: BMC sports science, medicine & rehabilitation
Published: 2025-11-24
Authors: Çağın M, Cicioğlu Hİ, Ertan H

## Question

How do acute traditional and reaction-based HIIT sessions affect EEG brain connectivity, Stroop responses, perceived exertion, and heart rate in elite athletes?

## Summary

In 33 elite young athletes, one acute 10-minute bodyweight HIIT session was compared with a reaction-cued version using colored light signals and a seated control condition. Both HIIT formats targeted 85% maximum heart rate; reaction-based HIIT produced higher perceived exertion despite similar heart rates and showed EEG connectivity changes interpreted as more cognitively demanding.

## Population

- Elite athletes from 11 sport branches
- Sample size: 33
- Age: 21.4 +/- 1.8 years
- Sex: 17 female, 16 male
- Fitness level: Elite athletes with 9.4 +/- 2.9 years sports history
- Health status: No reported acute conditions affecting physical or cognitive performance

## Methodology

- Randomized acute controlled experimental study
- Single acute measurement session
- Gazi University Faculty of Sports Sciences Wrestling Hall
- Randomized and controlled study design.

## Protocol

- Reaction-based HIIT.
- Modality: Bodyweight intervals with color reaction cues.
- Work intervals: 20 seconds.
- Recovery: 10 seconds, plus 1 minute between two rounds.
- Sets or repetitions: Ten cycles repeated twice.
- Intensity: 85% maximum heart rate.
- Session duration: 10 minutes HIIT after 5-minute warm-up.
- Frequency: Single acute session.
- Program length: Single session.
- Progression: None.
- Traditional HIIT.
- Modality: Bodyweight intervals without reaction cues.
- Work intervals: 20 seconds.
- Recovery: 10 seconds, plus 1 minute between two rounds.
- Sets or repetitions: Ten cycles repeated twice.
- Intensity: 85% maximum heart rate.
- Session duration: 10 minutes HIIT after 5-minute warm-up.
- Frequency: Single acute session.
- Program length: Single session.
- Progression: None.

## Outcomes

### Connectivity
Status: mixed
Reaction-based HIIT increased fronto-temporal synchronization; traditional HIIT showed changes in fronto-occipital and occipito-temporal regions.

Multiple significant group/time interactions were reported across frequency bands and electrode pairs.

### RPE
Status: worse/safety concern
Reaction-based HIIT produced higher perceived exertion than traditional HIIT.

Traditional 7.27 +/- 1.34 versus reaction-based 8.73 +/- 0.78; p=.003.

### Heart rate
Status: no clear change
Mean heart rate was similar between traditional and reaction-based HIIT.

Traditional 171.9 +/- 3.01 bpm; reaction-based 170.82 +/- 1.94 bpm; p=.162.

## Practical Insights

- Reaction cues can add cognitive load to familiar 20:10 bodyweight HIIT.
- Perceived difficulty may rise even when heart rate is similar.
- Use reaction-based HIIT cautiously for users who already tolerate the underlying movements.

## Limitations

- Acute-only design
- Small athlete groups
- No long-term adherence or performance outcomes
- EEG connectivity outcomes are not directly translatable to general fitness claims

## Safety And Adherence

- No adverse events were reported in the extracted text.
- Dizziness, blurred vision, or failure to complete HIIT were exclusion criteria.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/41286960/) (pubmed)
- [DOI](https://doi.org/10.1186/s13102-025-01400-2) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12642241/) (full text)

## Agent Guidance

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