PMID 28469752

Research
All papers

IL-6, Antioxidant Capacity and Muscle Damage Markers Following High-Intensity Interval Training Protocols

Cipryan L

Question

How do 15/15, 30/30, and 60/60 treadmill HIIT protocols with matched work differ in acute inflammatory, antioxidant, and muscle-damage markers?

Summary

In twelve moderately trained young men, three short treadmill HIIT formats with the same work-rest ratio all increased IL-6, antioxidant capacity, and muscle-damage markers after exercise. The 30-second format produced smaller IL-6 and myoglobin responses than the 15-second and 60-second formats.

Methodology

  • Twelve healthy moderately trained young men.
  • 12 participants.
  • Treadmill running.
  • Work intervals: 15, 30, or 60 seconds.
  • Recovery: Equal-duration active recovery.
  • Intensity: 100% vVO2max work; 60% vVO2max recovery.
  • 23 minutes.
  • Single acute session per protocol.
  • Three acute trials separated by 1-2 weeks.
  • Randomized-order acute crossover trial
  • IL-6, Total antioxidant capacity, and Muscle damage markers were tracked.

Outcomes

IL-6

All protocols increased IL-6; 15/15 and 60/60 produced larger effects than 30/30.

Effect sizes: 15/15 1.51, 30/30 0.84, 60/60 1.80.

Mixed

TAC

Total antioxidant capacity increased immediately after all protocols without major between-protocol differences.

Large immediate increases reported for all protocols.

Improved

Muscle markers

CK, myoglobin, and LDH rose after HIIT; myoglobin was lowest after 30/30.

Myoglobin effect sizes: 15/15 1.11, 30/30 0.45, 60/60 1.09.

Safety concern

Insights

  • Equal work/rest HIIT formats are not equivalent for acute muscle and inflammatory markers.
  • The 30/30 format may be a lower acute muscle-stress option than 15/15 or 60/60 in trained runners.

Limitations

  • Small all-male trained sample.
  • Acute-only outcomes.
  • Biomarkers are surrogate outcomes.
  • Glycogen and direct RONS were not measured.

Safety

  • No explicit adverse events, injuries, or symptoms were reported.
  • Safety-relevant findings were biochemical: muscle-damage markers rose after all HIIT formats; testing involved screening, lab supervision, medical blood draws, and post-exercise rest.