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Updated: Jul 3, 2026

A Real-World High-Intensity Interval Training Protocol for Cardiorespiratory Fitness Improvement
Published on: February 22, 2022
Aerobic interval training improves VO2 peak in coronary artery disease patients; no additional effect from hyperoxia
Trine Karlsen1, Jan Hoff, Asbjørn Støylen
1Department of Circulation and Medical Imaging, Faculty of Medicine, Norwegian University of Science and Technology, Trondheim, Norway. trine.karlsen@ntnu.no
Objectives:
To investigate whether hyperoxic aerobic interval training improves training quality in coronary artery disease patients.
Design:
Twenty-one stable coronary artery disease patients were recruited to hyperoxic (n=10) and normoxic (n=11) groups (age: 62.4 +/- 6.8 years). Patients underwent 30 supervised 44 minutes interval training sessions using treadmill walking, at 85-95% of peak heart rate.
Results:
Arterial saturation was significantly increased by 3% at pretest from normoxic to hyperoxic testing conditions. Peak oxygen uptake and stroke volume increased significantly by 16% and 17% (p<0.05) and by 16% and 18% (p<0.05) in the hyperoxic and normoxic training groups respectively. No difference was revealed between groups for peak oxygen uptake and stroke volume. Blood volumes were unchanged from pre to post training. Peak oxygen uptake measured in normoxia and hyperoxia in the hyperoxia training group revealed no difference.
Conclusion:
The present study shows that breathing 100% oxygen enriched air during aerobic interval training in stable coronary artery disease patients does not improve peak oxygen uptake above the level attained with normoxic training.
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