Rebreathing
Rebreathers and Cycling - from Jill
During the month of July, it can be difficult to get Robert’s attention in the morning. He is often head-down in his laptop watching the Tour de France, one of the greatest athletic feats in competitive sports. We share a deep love of cycling and admire the athletic prowess and toughness of men and women in the “sufferfest” of Grand Tour races. For up to three weeks at a time, elite athletes push their bodies to the limit, deploying marginal-gains-strategies to eke out a few seconds advantage and win the yellow jersey.
At times this beautiful sporting event has been tainted with controversy, often in the use of performance enhancing drugs. I’ve been serially disappointed by athletes such as Lance Armstrong, Alberto Contador and Floyd Landis—cyclists among the most notable names in the history of the Tour de France who have been caught doping. Their scandals have had a significant impact on the sport, leading to increased efforts to combat doping and restore the integrity of professional cycling. So I was a little surprised to read an obscure story this week involving cycling and the use of rebreathers. No, cyclists have not taken up technical diving, but they are experimenting with a controversial use of diving technology.
Journalists from the cycling media group Escape Collective reveal that several Tour de France teams may be using carbon monoxide (CO) rebreathers for training optimization at altitude. This practice, though risky, is a known technique in medical and research settings to measure key blood values. A more controversial use involves inhaling carbon monoxide gas to boost performance, potentially increasing VO2 max and aerobic capacity. While not banned by the World Anti-Doping Administration (WADA), this practice certainly may conflict with rules on artificial blood manipulation. There is currently no direct evidence that some top level World Teams use CO inhalation for performance, but concerns about its imminent use exist. Several teams admit to using rebreathers for testing purposes, not performance enhancement.
Research shows CO inhalation can mimic altitude training by inducing hypoxia, potentially replacing or enhancing traditional altitude training benefits. The technique is discussed in scientific circles, and its use in cycling is under scrutiny. WADA has not explicitly banned CO inhalation, but the practice raises ethical and safety concerns, as higher CO doses can cause severe health risks. Researchers and teams recognize the performance potential but remain cautious due to ethical considerations and the risk of abuse.
The use of CO rebreathers highlights the lengths to which cycling teams go for performance gains, emphasizing the thin line between legal optimization and unethical enhancement. For me, I will stick to using cycling to enhance my fitness and performance in diving!
Carbon Monoxide and Diving
Carbon monoxide (CO) poisoning in diving is typically related to contaminated breathing gas. This contamination can occur if the compressor used to fill the tanks has been exposed to exhaust fumes from cars running near a compressor intake. Mechanical issues in a poorly maintained compressor can also cause CO issues.
Mechanism of CO Poisoning
When CO is inhaled, it binds to hemoglobin in red blood cells with an affinity about 200-250 times greater than that of oxygen (O₂). This forms carboxyhemoglobin (COHb), which reduces the blood’s ability to carry oxygen to tissues and organs. With reduced oxygen-carrying capacity, tissues and organs, including the brain and heart, suffer from hypoxia (lack of oxygen). This can lead to headaches, dizziness, weakness, nausea, confusion, red fingernail beds and lips, and, in severe cases, loss of consciousness or death. CO also binds to myoglobin in muscles and cytochromes in mitochondria, further impairing cellular respiration and oxygen utilization at the tissue level.
Symptoms of CO Poisoning in Divers
Mild Exposure: Headache, dizziness, weakness, nausea, confusion, and shortness of breath.
Moderate Exposure: Chest pain, palpitations, impaired judgment, and visual disturbances.
Severe Exposure: Loss of consciousness, seizures, respiratory failure, and death.
It is a good day to take a walk on the Trans-Canada trail, which runs just in front of our place. The Trans-Canada out the front door, and the Mississippi out back!
We are so fortunate to live on the banks of the Mississippi River. Not the mighty Mississippi that spans all of the United States, from North to South, but the smaller Mississippi meandering through eastern Ontario, Canada. Our river joins the much larger Ottawa, then out to the St. Lawrence, and eventually to the Atlantic Ocean. Once again, everything we do in, on, and under our little Mississippi affects everything down stream. We are always aware of our responsibility to be good stewards of the little river that flows just outside our back door.
Book Recommendation - “Outlive” by Peter Attia, MD
Jill’s diving friend David Welch suggested she pick up a copy of this book about the “Science and Art of Longevity.” As I wear every one of my 67 years as a badge of honour, this is right up my alley. Needless to say, I’ve hoarded it and don’t think Jill has had a chance to read even the introduction. Unlike other health guides written by physicians, “Outlive” is not a plan to age gracefully, but rather to age fiercely - active and healthy - not only living longer, but living better. Admittedly, I am only about 1/4 of the way into this book, and it is not exactly light summer beach reading. But as a reference and guide I’m convinced that following Dr. Attia’s data driven advice, I can completely transform my approach to growing old. I’m not accepting that at a certain age, I’m going to fall apart and slow down. (Although I think my knees are well into their extended warranty program). And of course, being Jill’s partner sometimes requires super human mental and physical energy. I’m looking forward to delving deeper into “Outlive” and have already implemented a few of Attia’s recommendations about diet, exercise and sleep that are producing measurably positive results. Get your copy here.
Thanks for spending a bit of your valuable time with us today. If you know of someone who may enjoy The Explorer’s Mindset please forward this newsletter to them. Cheers! Jill and Robert
Yeah... I couldn't agree with you more. I was literally gobsmacked reading that article. I cannot understand how athletes can even live with themselves taking such risky measures and outright cheating. It kind of takes the joy out of the endeavour in my eyes!
Re- carbon monoxide as a "training" tool. Having a few decades as a firefighter, a permanent content of CO in my blood stream from a lifetime of CO exposure and lung damage that CO may have contributed to, I would just like to say: ARE YOU !@#$ MINDED #$%^& FILLED @#$% BRAIN-DAMAGED %$#@ #$%^ ME??? CO is not just a toxic poison used for executions, it cripples the body's pulmonary system with long term exposure. Just look at the chest x-rays of any 2 pack a day smoker after 20 years of smoking. "Performance enhancing"??? Why not just inject bleach into your bloodstream as suggested by a former US President! End of rant.