PMID 27536249

Research
All papers

Similar Inflammatory Responses following Sprint Interval Training Performed in Hypoxia and Normoxia

Richardson AJ, Relf RL, Saunders A, Gibson OR

Question

Do 2 weeks of sprint interval training in normoxia versus normobaric hypoxia produce different aerobic-performance adaptations and inflammatory responses?

Summary

In 42 untrained but recreationally active young adults, 2 weeks of all-out cycling sprint interval training improved VO2peak, time to exhaustion, and power at anaerobic threshold in both normoxia and hypoxia. Hypoxia did not exacerbate resting inflammatory responses compared with normoxia.

Methodology

  • Untrained but recreationally active young adults.
  • 42 participants.
  • Cycling.
  • Work intervals: 30 s all-out sprint.
  • Recovery: 4 min active cycling at 60 W.
  • Intensity: All-out against 0.075 kg/kg body mass.
  • Varied by sprint count.
  • 6 sessions over 2 weeks.
  • 2 weeks.
  • Randomized controlled training study with hypoxic SIT, normoxic SIT, and non-training control groups
  • VO2peak, Time to exhaustion, Inflammation, and Sprint performance were tracked.

Outcomes

VO2peak

VO2peak improved in hypoxia and normoxia but not control.

HYP +11.9%, p=0.001; NORM +9.8%, p=0.002; CONT +0.9%, p=0.906.

Improved

TTE

Time to exhaustion improved similarly in both SIT groups.

HYP 633 +/- 330 to 787 +/- 326 s; NORM 589 +/- 373 to 729 +/- 351 s; both p=0.001.

Improved

Inflammation

IL-6 and TNF-alpha increased after SIT, but hypoxia did not exacerbate the response versus normoxia.

IL-6 HYP +17.4%, NORM +20.1%; TNF-alpha HYP +10.8%, NORM +12.9%.

Mixed

Sprint power

Peak and mean Wingate power did not significantly change between groups.

Peak power pre-post p=0.530; mean power pre-post p=0.653.

No clear change

Insights

  • Six sessions of 30 s all-out cycling sprints can improve aerobic performance in young active adults.
  • A hypoxic chamber did not provide enough extra benefit to justify general use for most outcomes.
  • Inflammatory markers may remain elevated 48 h after the final SIT session.

Limitations

  • Short intervention
  • Young healthy sample
  • All-out cycling only
  • Hypoxic chamber setting
  • No explicit adverse-event reporting
  • Limited inflammatory markers

Safety

  • Adverse events were not reported.
  • Participants were informed of study procedures and risks, provided written consent, were non-smokers, and had no recent altitude exposure above 2000 m.
  • Training was supervised with HR, SpO2, and RPE monitoring, but attendance, dropout, and injury details were not reported in the main text reviewed.