Effect of Acute High-Intensity Interval Training on Immune Function and Oxidative Stress in Canoe/Kayak Athletes
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.
Methodology
- 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.
- 22 participants.
- Kayak ergometer paddling.
- Work intervals: 90 s maximum-intensity paddling.
- Recovery: 4 min passive rest.
- Intensity: Maximum intensity.
- 5 min warm-up plus 6 intervals and recoveries.
- Single acute session.
- Acute study.
- Acute single-group pre/post study
- Leukocytes, neutrophils, and lymphocyte subsets, LPS-stimulated neutrophil elastase release, Salivary IgA concentration, secretion, and flow rate, and Thiobarbituric acid reactive substances were tracked.
Outcomes
Immune cells
Leukocytes and neutrophils increased immediately and/or 3 h after HIIT, while lymphocyte percentage/count declined during recovery.
Neutrophil function
LPS-stimulated elastase release per neutrophil did not change, but total stimulated elastase release increased because neutrophil counts increased.
Salivary IgA
Salivary IgA concentration, secretion rate, and flow rate did not significantly change.
Oxidative stress
TBARS increased immediately post-exercise and returned toward baseline by 3 h; SOD and catalase increased after the interval bout.
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
- 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.