# Evaluation of the effect of high-intensity interval training on macular microcirculation via swept-source optical coherence tomography angiography in young football players

PMID: 34427215
Journal: Indian Journal of Ophthalmology
Published: 2021 Sep
Authors: Karaküçük Y, Okudan N, Bozkurt B, Belviranlı M, Tobakçal F

## Question

Does six weeks of running HIIT alter macular microcirculation measured by swept-source OCT angiography in young football players?

## Summary

This small before-after study in young male football players found that six weeks of supervised running HIIT changed central macular vessel-density measures, lowered pulse and intraocular pressure, and did not change several other ocular measures. It did not report adverse events.

## Population

- Healthy young male football players
- Sample size: 15
- Age: 18-20 years; mean 18.1 +/- 0.4
- Sex: Male
- Fitness level: Football players
- Health status: Healthy; ocular and systemic exclusions applied

## Methodology

- Prospective before-after study
- 6 weeks
- Football training and tertiary hospital ophthalmic measurement setting

## Protocol

- Running HIIT in football players.
- Modality: Running and walking.
- Work intervals: 90 seconds running.
- Recovery: 90 seconds walking plus passive rests between sequences.
- Sets or repetitions: 12 running bouts.
- Intensity: 90% HRmax.
- Session duration: Approximately 40 minutes; article wording unclear.
- Frequency: 3 sessions/week.
- Program length: 6 weeks.

## Outcomes

### Vessel density
Status: improved
Central deep and choriocapillaris vessel-density measures increased.

VDd central 18.7 to 21.1, p=0.002; VDcc central 54.5 to 56.9, p=0.002.

### IOP/pulse
Status: improved
Pulse and intraocular pressure decreased.

Pulse p=0.003; IOP p=0.017.

### Other ocular
Status: no clear change
Mean superficial vessel density, FAZ, CMT, and SFCT did not significantly change.

### Blood pressure
Status: no clear change
SBP, DBP, and oxygen saturation did not significantly change.

## Practical Insights

- The 90s run/90s walk format is reproducible but was tested in young athletes.
- Ocular microcirculation findings should remain mechanistic, not consumer health claims.

## Limitations

- Small sample.
- No control group.
- All-male young football players.
- No visual-function tests.
- Adverse events not reported.

## Safety And Adherence

- Adverse events were not reported.
- Participants were screened to exclude cardiovascular disease, hypertension, ocular disease, medication use, smoking, and alcohol use.
- Training was supervised by a coach with continuous heart-rate monitoring; one eligible participant dropped out because he did not attend the post-HIIT eye exam.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/34427215/) (pubmed)
- [DOI](https://doi.org/10.4103/ijo.IJO_3079_20) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8544043/) (full text)

## Agent Guidance

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