Can Training with Extra Oxygen Make Athletes Faster?
Yes. This study found that athletes who trained while breathing 60% oxygen improved their endurance by 117%, compared to only 50% improvement when training with normal air. The extra oxygen allowed them to train at 8.1% higher power outputs while maintaining the same heart rate.
Researchers wanted to test a simple idea. If athletes can work harder while breathing extra oxygen, could training at those higher intensities produce better results? This study put that theory to the test with a clever crossover design.
What the Data Show
- Performance improvement with hyperoxia: 117% increase (from 5.1 to 11.1 minutes at 90% VO2max)
- Performance improvement with normal air: 50% increase (from 5.6 to 8.5 minutes at 90% VO2max)
- Training intensity advantage: 8.1% higher power output (18 watts more) to maintain the same heart rate
- VO2max improvement: 8.3% with hyperoxia vs 6.0% with normal air (not statistically different)
- Training protocol: 10 intervals of 4 minutes at 90% max heart rate, 3 days per week for 6 weeks
- Sample size: 9 active but untrained subjects (mean VO2max of 51 mL/kg/min)
Dr. Kumar’s Take
This is a fascinating study that extends the “live high, train low” altitude training principle in a new direction. The researchers call it “live low, train even lower” since breathing 60% oxygen creates conditions effectively below sea level in terms of oxygen availability.
What stands out to me is the mechanism. The hyperoxia group didn’t just train with more oxygen. They trained at significantly higher power outputs because their target heart rate required more work to achieve. It’s the classic overload principle in action. By working harder during training, they got bigger performance gains.
The fact that VO2max improvements were similar between groups suggests the benefit comes from peripheral adaptations in the muscles rather than central cardiovascular changes. This makes sense since the lungs and heart aren’t the limiting factors for most people.
Study Design
Researchers used a single-blind crossover design. Nine subjects completed two 6-week training programs separated by 12 weeks of detraining.
During one program, subjects breathed normal room air (21% oxygen). During the other, they breathed a humidified gas mixture containing 60% oxygen through a mouthpiece. Subjects couldn’t tell which gas they were breathing due to the humidification and setup of the delivery system.
Both groups trained at the same heart rate (92% of maximum) three days per week for six weeks. Each session consisted of 10 intervals lasting 4 minutes, with 2 minutes rest between intervals.
Key Finding: Higher Training Intensity
The crucial difference was how much work subjects could do while maintaining their target heart rate.
When breathing 60% oxygen, subjects needed to pedal at an average of 18 watts higher power output to reach the same heart rate as when breathing normal air. Over the 6-week training period, this meant consistently training at higher intensities.
Both groups increased their power outputs as training progressed, showing they were getting fitter. But the hyperoxia group always trained at about 8% higher workloads.
Performance Results
After training, subjects were tested under normal air conditions to see how much they had improved. The test measured how long they could cycle at 90% of their baseline VO2max.
The hyperoxia group more than doubled their time, going from an average of 5.1 minutes to 11.1 minutes. The normal air group improved from 5.6 to 8.5 minutes.
This difference was statistically significant. The hyperoxia training produced substantially better performance gains than normal air training.
Why the Difference?
The researchers found no significant differences in cardiovascular responses between groups after training. Heart rate and breathing rate during submaximal exercise improved similarly in both conditions.
This suggests the performance advantage came from peripheral adaptations in the muscles rather than improved heart or lung function. The authors hypothesize that training at higher power outputs may have increased intracellular oxygen levels and muscle oxygen utilization.
Direct measurements of muscle changes would be needed to confirm this, but the pattern fits with the overload principle. Train harder, get more adaptation.
Practical Takeaways
- Training with supplemental oxygen allows higher training intensities at the same heart rate
- Higher training intensities can produce greater performance improvements
- The benefit appears to come from peripheral muscle adaptations rather than central cardiovascular changes
- This approach may help break through training plateaus where increasing intensity is difficult
- Results apply to interval training at high intensities (90% max heart rate)
Related Studies and Research
- Optimal type and dose of hypoxic training for improving maximal aerobic capacity in athletes: a systematic review and Bayesian model-based network meta-analysis
- Advances in hyperbaric oxygen to promote immunotherapy through modulation of the tumor microenvironment
- Normobaric oxygen treatment for mild-to-moderate depression: a randomized, double-blind, proof-of-concept trial
- Hypoxia and Inflammation
FAQs
Why didn’t VO2max improve more with hyperoxia?
Both groups improved their VO2max similarly (8.3% vs 6.0%), but the difference wasn’t statistically significant. VO2max is limited by the cardiovascular system’s ability to deliver oxygen. Since both groups trained at the same relative heart rate, they likely got similar cardiovascular adaptations. The performance difference came from peripheral muscle improvements.
Is 60% oxygen safe to breathe during exercise?
For the duration used in this study (40 minutes of intermittent breathing during exercise), 60% oxygen is considered safe. The gas was humidified to prevent airway irritation. Prolonged exposure to very high oxygen concentrations can cause lung irritation, but short-term use during exercise has not shown significant risks.
Can recreational athletes use this approach?
The equipment used in this study (compressed oxygen tanks, reservoir bags, precise delivery systems) would be impractical for most recreational athletes. However, commercial oxygen training systems do exist for gym and training facility use. The key insight is that the benefit comes from training at higher intensities, not from the oxygen itself.
How does this relate to altitude training?
Traditional altitude training uses the “live high, train low” model. Athletes live at altitude to stimulate red blood cell production but train at lower altitudes to maintain intensity. This study takes the opposite approach: living at sea level but training with extra oxygen to enable even higher intensities. The researchers suggest these approaches could potentially be combined.
Bottom Line
This study provides strong evidence that training while breathing 60% oxygen can significantly enhance performance gains compared to training with normal air. The key mechanism is that supplemental oxygen allows athletes to train at higher power outputs while maintaining the same target heart rate. Over six weeks, this 8.1% increase in training intensity translated to a 117% improvement in endurance performance versus only 50% for normal air training. While the specialized equipment makes this impractical for most recreational athletes, the study offers valuable insights into the importance of training intensity for performance gains.
