Is your cutie transfixed when you hold your breath? Mine is. Even if yours isn't, at least you have one.
I'm referring here to your cardiac QT interval. It's the period of time between the final 'wobble' of one heart beat, and the beginning of the next. A group of researchers at London's St Thomas's hospital are trying to find a link between this measurement and the mammalian dive reflex. Why?
Because some individuals that jump into cold water develop an arrythmia that can lead to sudden death.
The researchers needed to take ECG measurements of volunteers who were able to do something slightly unconventional while being monitored. Basically, plunging their heads into a basin of icy water, and keeping them there for as long as they could hold their breath for. The idea being to maximise the mammalian reflex for as long as possible.
The experiment hadn't worked too well with their sample group. This group consisting of medical students with an aversion to cold water and apnea. The 30 second samples they were getting were just too short - a good couple of minutes were required, but nothing in excess of four.
Enter the feediving community. This sounded straightforward enough, and a number of us volunteered.
There was an uncommon misconception. We assumed we could do our 'normal' thing - couple of minutes breathe-up, then head-down into the icy broth. The researchers on the other hand had a different expectation. Something along the lines of, "one deep breath and off you go". A breathe-up introduces physiological effects that skew the results.
Not being someone who likes to disappoint, I did things their way and managed to grimace my way through it. I was duly treated to "oohs" and "aahs" and, "didn't he do well?".
More importantly, the doctors had their first set of results over a time period that confirmed their predictions. They seemed pleased. My cutie was just as they'd imagined...
Saturday, July 25, 2009
Saturday, July 04, 2009
Synchronicity
You can teach an old dog new tricks. However, an old dog can forget old tricks too.
One old trick of this old dog, was making sure he knew when official time was at freediving competitions. Even if my dive computer wasn't synchronised to the microsecond, I always knew how far adrift it was.
The Blue Hole, Dahab, late May 2009, where Linda Paganelli and Lotta Ericson have put together a small depth competition. A good opportunity to dust the winter cobwebs off the equipment, and see if I can tag a few metres onto my free immersion NR. Attempting to do just that was when the time discrepancy kicked off the chain reaction.
I knew I was a minute or so ahead of official time, but as I made the first pull downward, it later transpired that over 10 minutes had passed since my final warm-up. For my physiology, not good news. Having reached my target of 70 metres, as I ascended I would normally expect a gradual slide into the 'struggle phase'. But this time, at 35 metres or so, the urge to breathe hit me in the thorax like the punch of a prize heavyweight fighter.
In fact, this was something of a double-whammy. Psychologically, the seeds of discontent were planted, and an expectation of a surface 'event' came to be.
Added to that, I lost mental focus and instead of concentrating on long, firm pulls, my head was elsewhere. An air of vulnerability crept in, and my arm pulls were feeble and inefficient. All the while valuable seconds ticked by, and when I eventually surfaced, my dive time that should have been less than two minutes 30, was a few seconds short of three minutes.
Then someone turned out the lights.
Fast forward four weeks, and the next event is Martin Zajec's pool competition in Prague. This time I'm not there to set records ( not that any pool-based freediving records are in my grasp anyway ); I'm there to try out my newly-acquired monofin technique. And to enjoy the experience and hopefully find a ranking.
I never get too worked up about static, I just go the standard distance and keep a close eye on any warning signs. However, that shouldn't justify complacency, or mean I could disregard my golden rule of competing - don't make last-minute changes.
I did. It was the wetsuit. Nice new Orca triathlon suit, perfect for dynamic, so why not use it for static too? OK, the limb thicknesses are a bit thin and there's no hood, but I assumed it would be fine.
I shivered my way to five minutes 22 seconds, kicking and fighting for half of it. Not pleasant, and a good deal shorter than where I should have been. All for the sake of a kilo or so of the right sort of neoprene.
These weren't my only two mistakes, but the others weren't lapses of memory or judgement, just bad habits I had been carrying around for some time.
Last but not least, I was pleased to discover in Prague that at least someone else out there reads my ramblings ( good to meet you Trux ). So as well as an aide memoire for me, perhaps others will find this stuff useful too.
One old trick of this old dog, was making sure he knew when official time was at freediving competitions. Even if my dive computer wasn't synchronised to the microsecond, I always knew how far adrift it was.
The Blue Hole, Dahab, late May 2009, where Linda Paganelli and Lotta Ericson have put together a small depth competition. A good opportunity to dust the winter cobwebs off the equipment, and see if I can tag a few metres onto my free immersion NR. Attempting to do just that was when the time discrepancy kicked off the chain reaction.
I knew I was a minute or so ahead of official time, but as I made the first pull downward, it later transpired that over 10 minutes had passed since my final warm-up. For my physiology, not good news. Having reached my target of 70 metres, as I ascended I would normally expect a gradual slide into the 'struggle phase'. But this time, at 35 metres or so, the urge to breathe hit me in the thorax like the punch of a prize heavyweight fighter.
In fact, this was something of a double-whammy. Psychologically, the seeds of discontent were planted, and an expectation of a surface 'event' came to be.
Added to that, I lost mental focus and instead of concentrating on long, firm pulls, my head was elsewhere. An air of vulnerability crept in, and my arm pulls were feeble and inefficient. All the while valuable seconds ticked by, and when I eventually surfaced, my dive time that should have been less than two minutes 30, was a few seconds short of three minutes.
Then someone turned out the lights.
Fast forward four weeks, and the next event is Martin Zajec's pool competition in Prague. This time I'm not there to set records ( not that any pool-based freediving records are in my grasp anyway ); I'm there to try out my newly-acquired monofin technique. And to enjoy the experience and hopefully find a ranking.
I never get too worked up about static, I just go the standard distance and keep a close eye on any warning signs. However, that shouldn't justify complacency, or mean I could disregard my golden rule of competing - don't make last-minute changes.
I did. It was the wetsuit. Nice new Orca triathlon suit, perfect for dynamic, so why not use it for static too? OK, the limb thicknesses are a bit thin and there's no hood, but I assumed it would be fine.
I shivered my way to five minutes 22 seconds, kicking and fighting for half of it. Not pleasant, and a good deal shorter than where I should have been. All for the sake of a kilo or so of the right sort of neoprene.
These weren't my only two mistakes, but the others weren't lapses of memory or judgement, just bad habits I had been carrying around for some time.
Last but not least, I was pleased to discover in Prague that at least someone else out there reads my ramblings ( good to meet you Trux ). So as well as an aide memoire for me, perhaps others will find this stuff useful too.
Monday, May 11, 2009
Good Directions
Time for a stake to be driven firmly into the ground. Something to indicate that 'Beyond The Big Blue' has returned, albeit with a different ( yet more relevant ) web address. All the old content has been migrated across, as I didn't want to lose some of the useful reference material.
Something of a renaissance, but with an altered slant. No longer being Press Officer of the BFA, my finger isn't quite so much on the pulse of freediving news. My new challenge is to write something that is useful for me, of interest to others, and that branches out....well, beyond the big blue!
Something of a renaissance, but with an altered slant. No longer being Press Officer of the BFA, my finger isn't quite so much on the pulse of freediving news. My new challenge is to write something that is useful for me, of interest to others, and that branches out....well, beyond the big blue!
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