Unproven athlete training and recovery devices

A recent Wall Street Journal article reported that #1 ranked Novak Djokovic and several other tennis players frequently spend time in hyperbaric chambers after matches. This supposedly helps athletes recover and prevents injury.

A hyperbaric pod

Malcolm Hooper, the owner of the Melbourne "clinic" where the hyperbaric pods are located and a former chiropractor, said he has "seen gains in his patients, and the research suggests hyperbaric treatment can help many ailments." The article also quoted several athletes who favored the treatment but cited none of the research.

Misconceptions about oxygen by alternative medicine practitioners

An article called “Simple ‘4-7-8′ breathing trick can induce sleep in 60 seconds” claims that this trick can get you to go to sleep within 60 seconds. All you have to do is the following:

♦ Exhale completely through your mouth, making a whoosh sound.
♦ Close your mouth and inhale quietly through your nose to a mental count of four.
♦ Hold your breath for a count of seven.
♦ Exhale completely through your mouth, making a whoosh sound to a count of eight.
♦ This is one breath. Now inhale again and repeat the cycle three more times for a total of four breaths

An integrative medicine expert, Dr. Andrew Weil, said it works because it allows the lungs to become fully charged with air, allowing more oxygen into the body, which promotes a state of calm.

“Promotes a state of calm” is nonsense. Let’s concentrate on the science. Does it allow more oxygen into the body? Ich don't think so.

The air we breathe contains about 21% oxygen. Nearly all oxygen in the blood is carried by hemoglobin. No matter how many deep breaths you take, you cannot get the oxygen saturation of hemoglobin (normally > 92%, closer to 98% in healthy people) above 100%. This is explained in more detail in a previous post of mine about why athletes don’t benefit from breathing pure oxygen after exertion.

This simple trick would be hard to remember but might work through the power of suggestion. It doesn’t cost anything, and unless you hyperventilate and pass out (but you'll be in bed anyway), it is harmless.

The next misconception about oxygen is neither inexpensive nor harmless.

Two naturopathic “doctors” have been accused of injecting a woman with oxygen or perhaps purified water that had been taken from an Octozone machine. The oxygen was supposed to destroy any pathogens in the woman’s blood. In the process of trying to kill the pathogens, the injection killed the patient who paid $500 for the treatment.

The naturopathic duo left town and were at large for several months before eventually being caught and charged with homicide.

An autopsy found her death was due to an air embolism.

According to a recent review of the subject, “Traditionally, it has been estimated that more than 5 mL/kg of air displaced into the intravenous space is required for significant injury (shock or cardiac arrest) to occur. However, complications have been reported with as little as 20 mL of air (the length of an unprimed IV infusion tubing) that was injected intravenously.”

Pure water should never be injected IV either because it causes blood cells to die from hemolysis.

How about we just take our oxygen the old-fashioned way—normal breaths and never intravenously?

Why supplemental oxygen is not considered a performance-enhancing drug

You often see a football player on the sidelines breathing oxygen after running a long distance or having worked hard during a long series of plays.

Have you ever wondered if it works? Does breathing a high concentration of oxygen help an athlete recover from exertion faster?

The answer is a resounding “No,” and here’s why.

In healthy people, such as college and professional football players, nearly all of the oxygen in the blood is carried by hemoglobin. Only a very small percentage is dissolved in blood. Saturation defines the oxygen that is attached to hemoglobin and partial pressure of oxygen is that which is dissolved in blood.

Definitions: SaO2 = arterial oxygen saturation, Hb = hemoglobin, 1.34 mL is the amount of oxygen a fully saturated gram of hemoglobin can carry, Pa02 = partial pressure of oxygen or the amount of oxygen dissolved in blood

If an athlete has a normal Hb level of 15 gm, a SaO2 of 100% and a PaO2 of 100 mmHg, the formula used to calculate his blood oxygen content is

[Hb X 1.34 X (SaO2/100)] + 0.003 X PaO2 or

[15 X 1.34 X 100/100] + 0.003 X 100

20.1 + 0.3 = 20.4 mL/100 mL of blood

So, only about 1.5% of the oxygen content of blood is dissolved.

If an athlete raises his PaO2 to 400 mmHg by breathing pure oxygen the calculation is

[Hb X 1.34 X (SaO2/100)] + 0.003 X PaO2 or

[15 X 1.34 X 100/100] + 0.003 X 400

20.1 + 1.2 = 21.3 mL/100 mL of blood

Even at a PaO2 of 400 mmHg, only 5.6% of the oxygen content of blood is dissolved. Note that hemoglobin cannot be more than 100% saturated with oxygen.

Very soon after the athlete stops breathing the pure oxygen, its minimal effect disappears. It’s simply not enough to affect recovery or performance.

Possibly because the basic science is well-understood, there have not been too many papers on this subject.

Here’s one from JAMA that looked at 12 soccer players given 100% oxygen or placebo after exertion. Then they had to exercise again. “The administration of enriched oxygen during the recovery period had no effect on plasma lactate levels [an objective measure of recovery] or on performance during the second period of exercise. The subjects were unable to identify which gas they received.”

A similar study of 13 athletes from Medicine & Science in Sports & Exercise concluded “These findings offer no support for the use of supplemental oxygen in athletic events requiring short intervals of submaximal or maximal exertion.”

Another from the European Journal of Applied Physiology found that giving athletes supplemental oxygen during the recovery periods of interval-based exercise improves the recovery time of SpO2 [equivalent to SaO2] but did not improve post-exercise markers of reactive oxygen species or inflammatory responses because the improvement in saturation was clinically insignificant.

The situation is explained in simple terms in an excerpt from the book Exercise Physiology: Integrating Theory and Application. It concludes that supplemental oxygen may have a placebo effect, but there is “no real physiologic benefit.”

If you Google “supplemental oxygen and athletes,” you will find a number of websites touting the supposed benefits of inhaled oxygen. They are almost all supported by companies that sell oxygen.

Bottom line: Supplemental oxygen is not considered a performance-enhancing drug because it doesn’t work.

Thanks to  Dr. Joel Topf (@kidney_boy ) for suggesting this topic.