# Acute Effects of High-Intensity Interval Training on Brain-Derived Neurotrophic Factor, Cortisol and Working Memory in Physical Education College Students

PMID: 33172145
Journal: International Journal of Environmental Research and Public Health
Published: 2020-11-06
Authors: Martínez-Díaz IC, Escobar-Muñoz MC, Carrasco L

## Question

What are the acute effects of a cycling HIIT bout on BDNF, cortisol, and working memory in healthy young men?

## Summary

A single bout of 10 x 1-min cycling HIIT at VO2peak power output increased BDNF immediately, increased cortisol through 30 min post-exercise, and improved digit-span working-memory scores immediately and partly at 30 min in 25 healthy male physical-education students. The study had no control group and no statistical association between biomarker changes and working-memory scores.

## Population

- Healthy male physical education college students.
- Sample size: 25
- Age: 21.7 +/- 2.1 years
- Sex: Male
- Fitness level: Physical education students; VO2peak 45.3 +/- 9.3 mL/kg/min
- Health status: Healthy with multiple neurological, psychiatric, metabolic, and medication exclusions

## Methodology

- One-group acute pre-post quasi-experimental study
- Single acute HIIT session
- University sport sciences laboratory

## Protocol

- Acute cycling HIIT.
- Modality: Cycle ergometer.
- Work intervals: 1 min.
- Recovery: 1 min passive.
- Sets or repetitions: 10 intervals.
- Intensity: VO2peak power output at 70 rpm.
- Session duration: About 20 min interval block.
- Frequency: Single session.
- Program length: Acute.
- Progression: None.

## Outcomes

### BDNF
Status: improved
BDNF rose immediately after HIIT and returned near baseline by 30 min.

424.66 +/- 91.05 to 1271.07 +/- 342.93 pg/mL; p<0.001.

### Cortisol
Status: worse/safety concern
Cortisol increased progressively through 30 min post-HIIT.

132.33 +/- 35.88 to 234.45 +/- 109.63 ng/mL at 30 min; p<0.001.

### Working memory
Status: improved
Digit Span backward and total scores improved immediately and remained partly elevated at 30 min.

DST-B and DST-T significant; effect sizes r=0.392-0.511.

### Correlations
Status: no clear change
Biomarker levels were not significantly associated with working-memory scores at matching timepoints.

No significant same-timepoint correlations.

## Practical Insights

- Acute HIIT may transiently improve working-memory test performance, but causality and real-world relevance are uncertain.
- High-intensity intervals produced large stress-marker responses.
- A 1:1 cycling format is reproducible but lab-calibrated intensity limits app translation.

## Limitations

- No control group
- Acute-only study
- All male physical education students
- Peripheral BDNF is an indirect central marker
- Potential BDNF genotype effects not assessed

## Safety And Adherence

- No adverse-event details were reported.
- Participants were screened to exclude cardiometabolic, neurological, psychiatric, endocrine, immunological, and medication-related risks.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/33172145/) (pubmed)
- [DOI](https://doi.org/10.3390/ijerph17218216) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7664431/) (full text)

## Agent Guidance

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