PMID 31359633

Research
All papers

Effects of all-out sprint interval training under hyperoxia on exercise performance

Kon M, Nakagaki K, Ebi Y

Question

Does performing all-out sprint interval cycling while breathing 60% oxygen change aerobic, anaerobic, repeated-sprint, and oxidative-stress adaptations compared with the same training in normal air?

Summary

In 18 male college canoe athletes, six sessions of all-out cycle sprint interval training improved VO2max in both normal air and hyperoxic conditions. Hyperoxia lowered submaximal lactate responses, suggesting some aerobic benefit, but normal air produced larger improvements in anaerobic capacity and repeated-sprint mean power. For practical training, adding extra oxygen is not a consumer-relevant enhancement and may blunt some anaerobic adaptations.

Methodology

  • Healthy male college athletes from a university canoe club who were already training for canoeing about 5 days per week.
  • 18 participants.
  • Cycle ergometer.
  • Work intervals: 30 seconds all-out.
  • Recovery: 4 minutes passive rest.
  • Intensity: All-out cycling against 7.5% body mass resistance while breathing 60% oxygen.
  • Approximately 20-30 minutes plus oxygen exposure from 10 minutes before exercise to immediately after.
  • 2 sessions per week on nonconsecutive days.
  • 3 weeks; 6 sessions.
  • Single-blind randomized training study
  • VO2max, Submaximal blood lactate curve, Anaerobic capacity, and Repeated-sprint power were tracked.

Outcomes

VO2max and maximal workload

Both normoxic and hyperoxic all-out SIT improved VO2max and maximal workload with no clear between-group advantage.

VO2max improvement NST 3.0 +/- 2.1%, HST 6.0 +/- 1.8%; group p=.83.

Improved

Submaximal blood lactate

Blood lactate during later submaximal stages decreased only after hyperoxic training.

HST stages 4 and 5 p<.05; effect sizes .80 and .86.

Improved

Anaerobic capacity

Accumulated oxygen deficit and percent AOD improved only after normoxic training, suggesting hyperoxia may blunt anaerobic adaptation.

Percent increases in AOD and %AOD were significantly greater in NST than HST; ES 1.07 and .92.

Mixed

Repeated-sprint mean power

Peak power improved in both groups, but average mean power improved only after normoxic training.

NST percent increase in average mean power significantly greater than HST; ES 1.12.

Mixed

Oxidative stress markers

Hyperoxia did not improve oxidative-stress markers; BAP decreased in both groups.

No clear change

Insights

  • All-out cycling intervals can improve VO2max quickly in trained young athletes.
  • Extra oxygen is not needed for consumer HIIT programming and may reduce anaerobic adaptation signals.
  • A 30-second all-out / 4-minute rest sprint protocol is performance-oriented and requires athlete screening and equipment.

Limitations

  • Small sample of trained male athletes only.
  • Short 3-week training period.
  • No crossover design.
  • Skeletal muscle adaptations were not measured.
  • Nutritional status was not objectively controlled.

Safety

  • No adverse events were described.
  • Participants were healthy trained athletes; the protocol is all-out and not directly appropriate for unscreened beginners.