Lymphocyte Redox Imbalance and Reduced Proliferation after a Single Session of High Intensity Interval Exercise
Question
Does one high-intensity interval cycling session affect lymphocyte proliferation, cytokine secretion, redox balance, and cell viability in healthy young men?
Summary
In healthy young men, one cycling HIIT session increased lymphocyte redox stress and reduced antigen-stimulated proliferation without showing an acute loss of cell viability. The protocol was tightly screened and supervised, but the paper did not report exercise adverse events.
Methodology
- Young non-smoking men not engaged in a regular exercise program.
- 16 participants.
- Cycle ergometer.
- Work intervals: 1 min at 90%-100% peak power.
- Recovery: 75 s at 30 W.
- Intensity: Study 1 100% peak power; Study 2 90% peak power.
- About 21 min including 2 min before and after.
- Single session.
- Single acute session.
- Two acute pre-post laboratory studies
- Lymphocyte proliferation, Redox status, and Cell viability were tracked.
Outcomes
SEB proliferation
SEB-stimulated proliferation decreased after HIIT.
P=0.02; non-dividing cells increased immediately post, p=0.05.
Redox markers
TBARS increased and CAT decreased 30 min post-exercise.
TBARS p=0.01; CAT p=0.03.
Cell viability
HIIT did not change viability, apoptosis, or necrosis.
Viability p=0.904; recent apoptosis p=0.711; late apoptosis p=0.329; necrosis p=0.053.
Insights
- A cycle-based 8 x 1 min protocol can produce measurable acute immune-cell redox stress.
- Acute biomarker stress is not equivalent to clinical harm, but it cautions against overstating immune benefits.
Limitations
- Small sample
- Men only
- Acute only
- No non-exercise control group
- Short follow-up
- Surrogate immune-cell outcomes
- No adverse-event reporting
Safety
- Exercise adverse events were not reported.
- Participants were screened with PAR-Q/coronary risk tools and exclusions for relevant diseases, injuries, anti-inflammatory drugs, immunization, and antioxidant supplements.
- Cell viability/apoptosis/necrosis did not significantly change after HIIT, but this is a laboratory safety-related biomarker rather than adverse-event monitoring.