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Step aside CBD oil and kinesio tape! There’s a new must-have performance-enhancing tool on the market: supplemental oxygen. It’s cheap, packable and proven to help give you that extra needed boost. Supplemental oxygen works by a simple formula— take in air, feel like air on the wall.
At the recent Bouldering World Cup in Vail, athletes could be seen packing supplemental oxygen cans into their iso bags. The trend started after Adam Ondra, an athlete that needs no introduction, used some in the qualification rounds. Ondra claimed they helped him adjust to the altitude, and that’s all it took. Semifinalists and finalists alike grabbed multiple cans for their bags the next day.
[Also Watch: Adam Ondra’s Road to Tokyo: Vail Bouldering World Cup]
Ondra wasn’t the first athlete to use supplemental oxygen (SO). In fact, the trend started over a century ago. One of the first papers on the topic was published in 1908. Tests were conducted on horses, marathon runners, weightlifters and even Jabez Wolfe, a man who narrowly missed the record for being the first person to swim across the English Channel. The encompassing conclusion: “Oxygen inhalation followed by, or accompanying exercise is a most active and effective form of treatment.”
There’s really no denying that SO has its time and place for augmenting athletic results. Perhaps the best example of its use is underwater breath holding. The world record for being underwater after having breathed pure oxygen is 24 minutes 3 seconds. The same record, but without the pure oxygen crutch, is half that— 11 minutes 35 seconds.
Still, the underlying mechanisms for the efficacy of supplemental oxygen are still not fully understood.
When it comes to the body’s use of oxygen, there are two main factors at play worth considering: oxygen delivery and oxygen uptake. Oxygen delivery is affected by the amount of blood-dissolved oxygen and hemoglobin oxygen saturation. Big picture, oxygen delivery is what’s affected by high altitude or SO—think oxygen availability. Oxygen uptake, on the other hand, is affected by genetic and metabolic factors unique to each individual.
Hemoglobin is the primary oxygen deliverer, but at sea level it is already adequately saturated. As altitude increases, hemoglobin saturation will slowly decrease. It should be noted, however, that even at 9,000 feet, average blood oxygen saturation will still be greater than 90%. 9,000 feet is slightly higher than the highest competition venue, Vail, Colorado, which sits at 8,150 feet. This would suggest that if a climber did use SO at elevation, very little would be needed to restore blood oxygen levels to normal.
The oxygen that is blood-dissolved is negligible. At sea level without SO, a person’s partial pressure of oxygen (amount of oxygen dissolved in blood) is 100 mmHG. Only about 1.5% of their oxygen content would be blood-dissolved. If that person increases the amount of oxygen in the blood to 400 mmHg via SO, that would increase the percent of available blood-dissolved oxygen to 5.6%. This would quickly decrease once the athlete stopped using SO.
Given that the climber was at a high altitude relative to what they were used to, it seems that the combined effect of increasing hemoglobin saturation and blood-dissolved oxygen could theoretically help a climber get that extra hold or two, but there aren’t any studies to back this up. For curious climbers, small bursts of SO in between climbs would seem the best strategy.
It’s worth noting, however, that there are plenty of studies that suggest that SO has no effect on athletic performance. This may be because the athletic activity in question requires the athlete to rely more on oxygen utilization rather than oxygen delivery. The more anaerobic (power-based) a sport it, the less oxygen delivery matters. Numerous studies have already shown that elite climbers rely more on the utilization of oxygen rather than the delivery. For example, a study published in 2015 compared blood flow and oxidative capacity as performance predictors. The study found that elite climbers “deoxygenated the flexor digitorum profundus significantly more and at a greater rate.” In other words, they were better at actually utilizing the oxygen that was delivered to their forearm. There were no significant differences in total forearm blood flow between non-climbers, intermediate, advanced and elite groups. It makes sense, too— climbing is mostly a power to power-endurance sport.
Nevertheless, besides oxygen blood flow, there’s another way supplemental oxygen could be useful to performance. The brain consumes roughly 20% of the body’s total oxygen supply, making it the body’s largest oxygen consumer. Even a slight reduction in available oxidized blood will adversely affect the brain’s ability to perform complex tasks. Studies have shown that hyperbaric oxygenation (using supplemental oxygen) can facilitate cognition in the elderly as well as healthy young patients. A 2017 study showed oxygen as the limiting factor for maximum brain performance and that at high altitudes. It also showed that both cognitive and motor skills may be improved with SO. These findings suggest that a climber using SO might be able to think better on the wall.
Also worth understanding are the possible dangers of using SO. According to one review study, as early as 1950 researchers noticed that SO can have adverse side effects. It decreases heart rate, thereby reducing cardiac output and increasing blood pressure. In 1969, a study concluded that “owing to the disproportionate reduction in cardiac output, SO did not increase oxygen transport in patients with arterial oxygen saturations of greater than 90%.” Because climbers are very unlikely to have a blood oxygen saturation of less than 90%, then this study would suggest that SO would not augment oxygen delivery. Perhaps the lowered heart rate could, however, keep the climber calmer? But it could also limit blood flow to the heart and muscles, which might actually limit performance and have potentially dangerous side effects.
So is supplemental oxygen worth the gas money? It’s a hairy question to answer. Maybe. It could help climbers think clearer or feel calmer. It makes since that at higher altitude it might support oxygen delivery. Then again, maybe the differences could be trivial.
Ultimately, try it at your own risk and see for yourself.
Thanks to my old CSU professor, Dr. Adam Chicco, for his help with the research.