# Comparison of Two Different Sprint Interval Training Work-to-Rest Ratios on Acute Inflammatory Responses

PMID: 27034919
Journal: Sports medicine - open
Published: 2016
Authors: Harnish CR, Sabo RT

## Question

Do two work-matched sprint interval protocols with different work-to-rest ratios produce different acute inflammatory and metabolic responses?

## Summary

In minimally active young adults, a single Tabata-style cycling session and a longer-rest Wingate-style session produced similar short-term cytokine responses and did not improve next-day insulin sensitivity.

## Population

- Minimally active healthy young adults
- Sample size: 15
- Age: 23.8 +/- 3.5 years
- Sex: 13 men, 2 women
- Fitness level: Minimally active; VO2peak 42.0 +/- 7.9 mL/kg/min
- Health status: Lean/healthy adults without diabetes, major metabolic disease, or high ACSM risk

## Methodology

- Counterbalanced crossover acute exercise study with intra-subject control period
- Acute sessions separated by at least 1 week
- Laboratory cycling and blood sampling
- Randomized and controlled study design.

## Protocol

- Tabata sprint interval cycling.
- Modality: Mechanically braked cycle ergometer.
- Work intervals: 20 s sprint.
- Recovery: 10 s recovery.
- Sets or repetitions: 10 sprints.
- Intensity: 5% body mass resistance; vigorous sprint effort.
- Session duration: 10 min unloaded warm-up plus interval set.
- Frequency: Single acute session.
- Program length: Acute crossover condition.
- Progression: No progression; acute work-matched protocol.
- Wingate sprint interval cycling.
- Modality: Mechanically braked cycle ergometer.
- Work intervals: 30 s sprint.
- Recovery: About 4 min unloaded/very slow pedaling.
- Sets or repetitions: 5 sprints.
- Intensity: 7% body mass resistance; vigorous sprint effort.
- Session duration: 10 min unloaded warm-up plus interval set.
- Frequency: Single acute session.
- Program length: Acute crossover condition.
- Progression: No progression; acute work-matched protocol.

## Outcomes

### Insulin sensitivity
Status: worse/safety concern
Insulin sensitivity was lower 24 h after both sprint protocols.

TAB -2.8 (95% CI -5.1 to -0.5); WIN -3.9 (95% CI -6.9 to -0.9); no between-protocol difference

### Cytokines
Status: mixed
IL-6, IL-10, and TNF-alpha rose acutely and returned toward baseline by 24 h in both protocols.

No cytokine group differences reported

### Work-to-rest ratio
Status: no clear change
Different work-to-rest ratios did not meaningfully alter inflammatory or metabolic responses when total work was matched.

Total work TAB 64.7 +/- 12.0 kJ vs WIN 68.0 +/- 15.0 kJ, p = 0.515

### Heart rate
Status: mixed
The Tabata condition produced higher heart rate despite similar work and lactate.

TAB 180.7 vs WIN 173.9 beats/min, p = 0.0272

## Practical Insights

- Changing rest ratio alone may not change short-term cytokine response if total work is matched.
- Very short-rest Tabata cycling can impose higher cardiovascular strain than longer-rest Wingate cycling.
- Acute inflammatory marker changes should not be interpreted as chronic adaptation.

## Limitations

- Acute-only study
- Small sample with mostly men
- Healthy, lean, young adults
- No chronic training outcomes
- Cycling-specific protocol

## Safety And Adherence

- No explicit adverse-event outcome was reported; one participant missed a 24 h Wingate follow-up because of inclement weather.

## Original Sources

- [PubMed](https://pubmed.ncbi.nlm.nih.gov/27034919/) (pubmed)
- [DOI](https://doi.org/10.1186/s40798-016-0044-1) (doi)
- [PMC full text](https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4773496/) (full text)

## Agent Guidance

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