# New insight of high-intensity interval training on physiological adaptation with brain functions

PMID: 30343552
Journal: Journal of exercise nutrition & biochemistry
Published: 2018 Sep 30
Authors: Min Chul L, Sung Ki L, Suk Yool J, Hyung Hoon M

## Question

What is known about physiological adaptation to high-intensity interval training and its possible effects on brain function?

## Summary

This narrative review summarizes evidence that high-intensity interval training can improve aerobic and skeletal muscle adaptations and may support brain plasticity and hippocampus-related learning and memory. The article is not an original trial, so its claims are background context rather than direct evidence from a tested HIITplay-style program.

## Population

- No original participant sample; the review discusses human HIIT studies and animal/exercise models relevant to skeletal muscle and brain adaptation.

## Methodology

- Narrative review

## Protocol

- Reviewed HIIT and sprint interval models.
- Modality: Primarily cycling sprint interval training and intermittent high-intensity exercise models.
- Work intervals: Examples include about 20-90 seconds of high-intensity work; a common Wingate model uses 30-second all-out cycling bouts.
- Recovery: Examples include low-intensity or passive recovery; a reviewed Wingate model used about 4 minutes recovery.
- Sets or repetitions: Examples include 4-6 all-out bouts.
- Intensity: Maximum effort or very high intensity in sprint interval examples.
- Session duration: Often described as under 30 minutes; a reviewed low-volume Wingate model was about 20 minutes including recovery.
- Frequency: Example protocols include 3 sessions per week.
- Program length: Varies across cited studies.

## Outcomes

### Aerobic fitness
Status: improved
The review states that HIIT improves aerobic capacity while requiring less exercise time than traditional endurance training.

### Muscle signaling
Status: improved
The review describes HIIT-induced activation of signaling pathways linked to mitochondrial and metabolic adaptation, including PGC-1alpha-related pathways.

### Brain plasticity
Status: mixed
The review argues that intermittent high-intensity exercise may enhance hippocampus-related learning and memory through BDNF-related mechanisms, but much of this evidence is indirect.

## Practical Insights

- Short, intense bouts with recovery are a common HIIT structure, but the review does not test a single prescription.
- Brain-health claims from this article should be framed as plausible mechanisms or hypotheses, not proven user outcomes.
- The review notes that clinical or less-conditioned populations may need moderated intervals rather than all-out sprint formats.

## Limitations

- Narrative review rather than an original trial.
- No systematic search, pooled effect estimates, or reproducible intervention protocol are reported.
- Brain-function evidence combines animal models, mechanistic pathways, and indirect human evidence.
- Safety and adherence are discussed generally, not measured prospectively.

## Safety And Adherence

- The review notes concern that HIIT popularity may be associated with injury risk if high-intensity exercise is used inappropriately.
- The authors suggest clinical fitness professionals may substitute moderate-intensity intervals for some patients.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/30343552/) (pubmed)
- [DOI](https://doi.org/10.20463/jenb.2018.0017) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6199482/) (full text)

## Agent Guidance

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