[Ol Dirty Diver]

I actually don't think I'm hyperventilating; I've definitely been made aware of its pitfalls from the numerous posts criticizing it. I suppose 'deep breathing' is ambiguous, and can mean many types of breathing. To be more specific, my 'deep breathing' entails very technique-focused, slow breathing. I begin by pushing my belly out to fill the lower lungs, then fill my upper lungs, which takes ~6 sec. I don't hold my breath at all at peak inspiration, instead progressing right into my exhale. I focus on making my exhale as slow as possible, at least twice as long as the inhalation, with a finish that involves drawing my diaphragm/belly in as much as possible.

If that qualifies as hyperventilation, then I've been doing it inadvertently all this time even though I've been trying to avoid it! I actually realized my so-called "belly-breathing" method on my own, when I started running and learned that it was a way to alleviate and avoid my frequent stomach cramps (the mechanism of which was through relaxing my diaphragm muscle, which was contracted too much, thereby producing the cramp). Through some reading I recognized how similar my form of breathing sounded to proper deep breathing in preparation for apnea. I think I also gathered some support for it through hearing the mention of making the exhalation at least twice as long as the inhalation during the David Blaine TV special (I think Kirk Krack discussed it).

Just wanted to offer that clarification in case you were dismissing my inquiry due to believing that I was hyperventilating (correct me if I am still wrong after hearing my explanation). Does my form of deep breathing actually differ from what experienced apneists do? I feel like I drastically improved my apnea potential when I began implementing it. Anyway, I do notice that my heart rate can drop a few beats during the long slow exhalation of a deep breath (whereas it rises during the inhalation), but my avg. heart rate during the deep breathing is nevertheless ~20 beats higher than when I breathe normally. One of my inquiries posed the question of whether this seemingly necessary rise in heart rate associated with deep breathing was unfavorable enough that deep breathing should be avoided except right before the breath-hold. I don't know why, but for some reason I've always done deep breathing throughout my apnea preparation phase, and now I'm questioning whether this is appropriate or detrimental.

Thanks for your help.