Silent Bubbles and Fatigue or Tiredness

[dfx]

The comparison is not between a diver diving nitrox and another staying on the surface. The comparison in question is between a diver using nitrox and a diver using air, presumably both diving the same depth profile. In which case, the diver using nitrox is inhaling a higher O2 percentage if they are both at the same depth.

My point was that at depth, you already have way more oxygen available to you in your breathing gas than you could ever possibly metabolize. Thus, an ever higher amount of oxygen isn't gonna give you any sort of boost.

 

[Bopper]

The paper in the second link mentions ascent times. Be careful with slowing your ascents when you're deeper as this can not only slow your off-gassing but also cause some tissues to continue to on-gas. Also, make sure that your regulator is adjusted properly and that you are adequately (but not excessively) hydrated.

Best regards,
DDM

Well a year later, I think you've nailed it. I've always known that a maladjusted regulator might cause CO2 retention. However, I dive what's considered one of the easiest breathing regs (Mk25/S600). And I would take my reg to get serviced by a professional. So I just assumed that my reg couldn't be the culprit. But after your comment I decided to experiment.

On the surface of the water I cranked on the adjustment knob until the regulator went into free flow. Then I backed it off until the free flow stopped. For the life of me during the dive I could not tell the difference in the rate of flow of the air or the ease of breathing at any water level. But the results speak for themselves: I've gone on many multiple intra-day dive trips since then. My headaches are effectively gone. Whereas previously I would expect to get a headache after 2 - 3 dives and have to skip a 4th or 5th dive, now I can dive right through the day without even a hint of a headache.

My fatigue seems to have gone down considerably as well. It's still definitely there. But whereas I would previously feel like a lead weight looking for the nearest bed, on my most recent multi-dive trip I tried to go to sleep for a nap after a few dives and I couldn't fall asleep. Normally I'd fall sound asleep with a headache and really dread the idea of diving more that day.

Also, I do a lot of one off shore dives here in San Diego. It used to be that after one dive on the weekend I'd want to go home and take a nap. But lately I've found myself skipping the nap altogether. Like I said, I find that I'm still tired; I think a lot of divers get fatigued, and I can still get very tired. But it seems to be significantly less than before. Don't know if this all has to do with my regulator adjustment; there can always be another variable that has changed that I'm not aware of. But the regulator is the only thing I've changed consciously. So I thought I'd come back and share my experience with others as they might benefit from it.

And also wanted to say thanks for all the advice and insight! Sometimes the solution is right under your nose...literally.