# Lymphocyte Redox Imbalance and Reduced Proliferation after a Single Session of High Intensity Interval Exercise

PMID: 27096389
Journal: PloS one
Published: 2016
Authors: Tossige-Gomes R, Costa KB, Ottone Vde O, Magalhães Fde C, Amorim FT, Rocha-Vieira E

## 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.

## Population

- Young non-smoking men not engaged in a regular exercise program.
- Sample size: 16
- Age: Study 1: 23.7 +/- 1.1 years; Study 2: 21.3 +/- 1.8 years
- Sex: Men only
- Fitness level: Not engaged in regular exercise; VO2peak about 33.6-36.6 mL/kg/min.
- Health status: Healthy by self-report and screening; major cardiovascular, pulmonary, autoimmune, neuromuscular, and musculoskeletal issues excluded.

## Methodology

- Two acute pre-post laboratory studies
- Single acute session
- Environmental chamber and laboratory blood analysis

## Protocol

- Acute cycling HIIT.
- Modality: Cycle ergometer.
- Work intervals: 1 min at 90%-100% peak power.
- Recovery: 75 s at 30 W.
- Sets or repetitions: 8 intervals.
- Intensity: Study 1 100% peak power; Study 2 90% peak power.
- Session duration: About 21 min including 2 min before and after.
- Frequency: Single session.
- Program length: Single acute session.
- Progression: None.

## Outcomes

### SEB proliferation
Status: worse/safety concern
SEB-stimulated proliferation decreased after HIIT.

P=0.02; non-dividing cells increased immediately post, p=0.05.

### Redox markers
Status: worse/safety concern
TBARS increased and CAT decreased 30 min post-exercise.

TBARS p=0.01; CAT p=0.03.

### Cell viability
Status: no clear change
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.

## Practical 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 And Adherence

- 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.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/27096389/) (pubmed)
- [DOI](https://doi.org/10.1371/journal.pone.0153647) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4838252/) (full text)

## Agent Guidance

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