This last Monday night at our Freedive Toronto pool practice, I experienced my first ever blackout of any kind during static practice. This was not the standard hypoxic BO we think about when we're thinking about breathhold related blackouts however! I blacked out at about 5 seconds total time.
On my previous attempt I purged 5 times, and packed 6 times. I got a slight headrush, but it was in the "I've had worse" catagory! (I've had hypocapnic LMC several times, yes I know that this isn't ok!!:naughty ) I also noticed that I didn't feel any real pressure on my epiglotis during that static, so I decided to pack 8 times for my third attempt.
On my third and final attempt, I purged 5 times and packed 8 times after a 3-4 minute breathe-up. I went down, and almost immediatly felt the very early symptoms of hypocapnia, just a slight buzz. Much less than on my previous attempt. The next thing I knew I was being supported at the side of the pool being told to "breathe-breathe!" I was fully aware instantly that something had gone wrong, but I didn't know if I had finished my static and blacked out at the end, or anything else.
My spotter said that I went down, and at about 5-7 seconds I started releasing air. He said he remembered a time that he went down and a funny thought interupted his concentration and he laughed under water! He thought that possibly the same thing was happening to me, and he expected me to abort my attempt as I had obviously exhaled almost all my air. After 5 further seconds though when I failed to stand up or respond to a signal, he tried to lift me out of the water. I was obviously very limp at this point, and he had a bit of a struggle supporting my head above the water. At about 15-20 seconds total time I regained conciousness.
I have one point and a question as well.
To those of you who dive solo, (as I used to!) I had no warning that I was going to black out. It felt like a very slight buzz at most, not the "going down the tunnel" effect that I feel before a hypocapnic LMC. If I had been solo, I don't know if I would've regained conciousness before inhaling a lungfull of water or not.
Question to those of you who have experienced this type of blackout before: Did you know you were going out? What did you change to ensure that this didn't continue to happen? I know the obvious answer is to purge less, however I have purged 7 times and packed 10 times before with little to no headrush at all. Different day effect I guess.
Thanks for your imput,
Aaron
On my previous attempt I purged 5 times, and packed 6 times. I got a slight headrush, but it was in the "I've had worse" catagory! (I've had hypocapnic LMC several times, yes I know that this isn't ok!!:naughty ) I also noticed that I didn't feel any real pressure on my epiglotis during that static, so I decided to pack 8 times for my third attempt.
On my third and final attempt, I purged 5 times and packed 8 times after a 3-4 minute breathe-up. I went down, and almost immediatly felt the very early symptoms of hypocapnia, just a slight buzz. Much less than on my previous attempt. The next thing I knew I was being supported at the side of the pool being told to "breathe-breathe!" I was fully aware instantly that something had gone wrong, but I didn't know if I had finished my static and blacked out at the end, or anything else.
My spotter said that I went down, and at about 5-7 seconds I started releasing air. He said he remembered a time that he went down and a funny thought interupted his concentration and he laughed under water! He thought that possibly the same thing was happening to me, and he expected me to abort my attempt as I had obviously exhaled almost all my air. After 5 further seconds though when I failed to stand up or respond to a signal, he tried to lift me out of the water. I was obviously very limp at this point, and he had a bit of a struggle supporting my head above the water. At about 15-20 seconds total time I regained conciousness.
I have one point and a question as well.
To those of you who dive solo, (as I used to!) I had no warning that I was going to black out. It felt like a very slight buzz at most, not the "going down the tunnel" effect that I feel before a hypocapnic LMC. If I had been solo, I don't know if I would've regained conciousness before inhaling a lungfull of water or not.
Question to those of you who have experienced this type of blackout before: Did you know you were going out? What did you change to ensure that this didn't continue to happen? I know the obvious answer is to purge less, however I have purged 7 times and packed 10 times before with little to no headrush at all. Different day effect I guess.
Thanks for your imput,
Aaron