# Effect of Acute High-Intensity Interval Training on Immune Function and Oxidative Stress in Canoe/Kayak Athletes

PMID: 37627028
Journal: Biology
Published: 2023 Aug 18
Authors: Lee TT, Li TL, Ko BJ, Chien LH

## Question

What acute effects does a conventional kayak high-intensity interval session have on immune function and oxidative-stress responses in well-trained canoe/kayak athletes?

## Summary

A single kayak-ergometer HIIT session in well-trained male canoe/kayak athletes acutely changed immune-cell profiles and oxidative-stress markers. Some markers returned toward baseline within 3 hours, but the authors cautioned that high frequency or inadequate recovery could temporarily suppress immune function.

## Population

- Twenty-two well-trained male kayak athletes, mean age 15.9 years, with at least 3 years training history and more than 3 sessions/week in the prior 3 months, recruited during a training camp under the same coach.
- Sample size: 22
- Age: Mean 15.9 years
- Sex: Male
- Fitness level: Well-trained kayak athletes
- Health status: Athletes without allergies, immune disease, or recent muscle injury

## Methodology

- Acute single-group pre/post study
- Single acute session with immediate and 3 h follow-up
- Training camp/testing environment using kayak ergometer

## Protocol

- Kayak ergometer acute HIIT.
- Modality: Kayak ergometer paddling.
- Work intervals: 90 s maximum-intensity paddling.
- Recovery: 4 min passive rest.
- Sets or repetitions: 6 repetitions.
- Intensity: Maximum intensity.
- Session duration: 5 min warm-up plus 6 intervals and recoveries.
- Frequency: Single acute session.
- Program length: Acute study.
- Progression: No progression.

## Outcomes

### Immune cells
Status: mixed
Leukocytes and neutrophils increased immediately and/or 3 h after HIIT, while lymphocyte percentage/count declined during recovery.

### Neutrophil function
Status: mixed
LPS-stimulated elastase release per neutrophil did not change, but total stimulated elastase release increased because neutrophil counts increased.

### Salivary IgA
Status: no clear change
Salivary IgA concentration, secretion rate, and flow rate did not significantly change.

### Oxidative stress
Status: mixed
TBARS increased immediately post-exercise and returned toward baseline by 3 h; SOD and catalase increased after the interval bout.

## Practical Insights

- Very hard repeated 90 s kayak intervals can produce short-term immune and oxidative-stress perturbations in trained athletes.
- Recovery timing matters when scheduling frequent high-intensity sessions.
- Acute biomarker changes should not be treated as evidence of long-term health or performance adaptation.

## Limitations

- Single-group acute design with no control condition.
- Small sample.
- Male canoe/kayak athletes only, many adolescents.
- Participants came from the same local training environment and may not represent other athletes.
- Age range included different developmental stages that could influence immune responses.

## Safety And Adherence

- No adverse events were reported. Participants were screened for allergies, immune disease, and recent muscle injury and were asked to avoid alcohol, smoking, medical treatment, and supplements.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/37627028/) (pubmed)
- [DOI](https://doi.org/10.3390/biology12081144) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10452436/) (full text)

## Agent Guidance

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