Nitrox?

[MaxBottomtime]

 

[tursiops]

I can't bear to watch this guy again. Can you summarize whatever point you are trying to make by offering him?

 

[MaxBottomtime]

He explains the placebo effect with nitrox.

 

[scubadada]

I have discussed this with a person who is a professor of Pharmacology, A fellow of the Royal Society of Pharmacologists and the former head of imaging sciences at a University. Her opinion is that raising the oxygen concentration will be beneficial. Not quite a direct comparison but consider the effects of EPO on athletes performance. The aim is to get more oxygen to the muscles.

Best of intentions, this is wrong. Under normal conditions, breathing air, your hemoglobin in your RBCs is essentially fully saturated. Breathing oxygen does not change this to an any significant degree.

Athletes taking erythropoietin increase their RBC count and thus increase their oxygen carrying capacity. The same thing can be done by training at altitude or with transfusion. Taking EPO or transfusion is generally not allowed in organized athletics.

 

[60plus]

Best of intentions, this is wrong. Under normal conditions, breathing air, your hemoglobin in your RBCs is essentially fully saturated. Breathing oxygen does not change this to an any significant degree.

Bear in mind this is just a brief post. The professor did not mention EPO, I added that but I did state "not quite a direct comparison", I know how EPO works. Diving where the issue is increased nitrogen take up is not normal conditions.
With regard to the fatigue question you can find plenty of statements that say "studies have shown that nitrox does not reduce fatigue" or words to that effect but they never quote the study or if it is properly peer reviewed. You can also find plenty of what appear to be authoritative reports that state nitrox does reduce fatigue. What the professor said was "raising the oxygen concentration will be beneficial" and this is because when the body suffers from any one or more of many types of problem giving oxygen was beneficial. To give common examples it increases the rate of healing of flesh and bone in particular and greatly reduces migraine in some people. Her view is that the result of extra oxygen will be a reduction in fatigue, not because the oxygen directly reduces fatigue but because it slows the rate of accumulation of nitrogen that will cause fatigue. Again its a bit different but I clearly notice an increase in fatigue when skiing at between 2000 and 3000 meters as compared to skiing at less than 1000 meters and the reason is the reduction in oxygen.
It would be very interesting to have a proper test done using a treadmill or rowing machine, giving some participants nitrox and others air and noting the difference in power output and recovery times between the two gases.

 

[scubadada]

I doubt there will ever be a well-designed, adequately powered clinical trial to answer the question regarding fatigue in air vs. nitrox diving. The design of such a trial is not the difficult part. Having an acceptable, validated measurement tool for fatigue is the major impediment. Who would pay for such a trial, this is not an important question in diving.

I can't remember the last time I dived air, I cannnot make the comparison. I appreciate the longer bottom times and reasonable SIs afforded by diving nitrox. My RMV is reasonable, I enjoy having more dives not limited by my NDL.

I do not argue with folks claiming a fatigue advantage with nitrox, it is subjective. To each their own.

 

[formernuke]

I do not argue with folks claiming a fatigue advantage with nitrox, it is subjective. To each their own.

This

 

[60plus]

Diving Hyperb Med

. 2010 Sep;40(3):114-8.

Evaluation of critical flicker fusion frequency and perceived fatigue in divers after air and enriched air nitrox diving​

Pierre Lafère 1, Costantino Balestra, Walter Hemelryck, Nicola Donda, Ahmed Sakr, Adel Taher, Sandro Marroni, Peter Germonpré
Affiliations expand

• PMID: 23111908

Abstract​

Introduction: Many divers report less fatigue following dives breathing enriched air nitrox (EANx) compared with breathing air. A reduction of post-dive fatigue with EANx would suggest a pathological origin, possibly the presence of asymptomatic nitrogen bubbles in the body after a dive.
Method: We studied fatigue in 219 healthy divers performing either an air (n = 121) or EANx32 (oxygen 32%, nitrogen 68%; n = 98) dive to 21.2 ± 4 metres' sea water for 43.3 ± 8.6 minutes in tropical open-water conditions. Divers were assessed pre-dive and 30-60 minutes after surfacing using a visual analog scale (VAS) of fatigue and critical flicker fusion frequency (CFFF).
Results: The two groups were comparable in sex ratio, age and diving experience. The change in perceived fatigue level after a single dive was significantly lower when EANx was breathed compared to air dives (VAS; P < 0.001). Compared to pre-dive, CFFF decreased by 6% in the air group (P < 0.01) but increased by 4% in the EANx group (P < 0.05). The post-dive difference between the two groups was highly significant (P < 0.001).
Conclusions: Three hypotheses should be considered to explain the difference in post-dive fatigue and alertness between the air and EANx groups: a nitrogen effect, an oxygen effect and a bubble effect. These involve complex phenomena in the functional modifications of the nervous system in hyperbaric environments according to the type of gas used for the dive, and more research will be required to elucidate them.

 

[MaxBottomtime]

https://d1wqtxts1xzle7.cloudfront.net/43911541/Evaluation_of_critical_flicker_fusion_fr20160320-14736-1kuvlw9-libre.pdf?1458459776=&response-content-disposition=inline%3B+filename%3DEvaluation_of_critical_flicker_fusion_fr.pdf&Expires=1676769769&Signature=BD9qoBBbrLrzo4ZYEmQX5EON2ivbE-Aru1UjZkxjdcYO6x3cTro1XrKhMBKOM4v35IFqBiCbvCJKT2D4oS-uyErOgWyR3VlHOm8m3MiJHvn2hc5dMeGwE9Y-MlYAlphrD9N7mFFwhmkfY~agTAv0t2lIwOvtbyl4-u-rA-EXu4fUbWfqtYTdVHkG1Ikc4ZVmscsXkL77I0Cx-Zn1TnuIXVRJgW7umjzhKy7Ep0yuNOEHYNOdUXfzEUeGdl9Io8nCJY~uVRd27L12ABHSKc9MpOxP~2B~spbhLPZLdQeup1YgD2lJI4o9m-WBGVOcWODvJ4cB4OHUoXt2TvnruoDOAQ__&Key-Pair-Id=APKAJLOHF5GGSLRBV4ZA

 

[Eric Sedletzky]

Just like all that deep breathing when I used to freedive a lot. My body and brain would get oxygenated and I felt great. When I dive nitrox my body and brain get more oxygenated with the increased PPO2 and less N. I have great more vivid dreams and I feel great!
Screw all of you, you can debunk all you want I don’t buy it.
I love my nitrox and YES it makes me feel better!