PMID 27034919

Research
All papers

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

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.

Methodology

  • Minimally active healthy young adults
  • 15 participants.
  • Mechanically braked cycle ergometer.
  • Work intervals: 20 s sprint.
  • Recovery: 10 s recovery.
  • Intensity: 5% body mass resistance; vigorous sprint effort.
  • 10 min unloaded warm-up plus interval set.
  • Single acute session.
  • Acute crossover condition.
  • Counterbalanced crossover acute exercise study with intra-subject control period
  • Insulin sensitivity, Cytokines, Lactate, and Heart rate were tracked.

Outcomes

Insulin sensitivity

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

Safety concern

Cytokines

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

No cytokine group differences reported

Mixed

Work-to-rest ratio

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

No clear change

Heart rate

The Tabata condition produced higher heart rate despite similar work and lactate.

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

Mixed

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

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