A Winter Training Program for Freedivers:Part I
Posted By Aharon & MT Solomons on 28 November 2005
Editor's Note: Traveling as I am in the Northeastern United States, I've become acutely aware that many of our freediving colleagues reside in areas that become atrociously cold during the winter months. Not so in sunny South Florida, which I call home, but compassion drives me to post this superb training series for the sake of all those in the extreme latitudes. Here's looking at you, kids...
THE PURPOSE of this series of articles is to address the value to the freediving community of a Winter Freediving Program suited to the BEGINNER or INTERMEDIATE student. When summer arrives and freedivers once again have access to warm water they ought to be in the BEST condition possible.
The primary emphasis must be safety: knowing what the dangers are, how to avoid them and how to deal with problems should they arise. Pool training is a very safe activity IF the safety rules are respected, but is about the equivalent of Russian roulette if they are not.
At the end of this article you should have a good idea of how to set up SAFE dynamic and static apnea practice sessions. The tables that are presented here are adaptations of the standard tables of the Apnea Academy of Umberto Pelizzari. There are other tables, and we have developed very different ones that we teach in our Advanced courses. However, my advice to the beginner or intermediate freediver is that the tables presentd here are superb tools for achieving 4:00 -- 5:00 minute breath-holds and learning one's body, its reactions and capabilities. This, in my opinion, is absolutely necessary before going on to 'empty lung' work and more advanced techniques.
BREATH-HOLD is considered to have 2 distinct phases, the so-called, 'Easy Phase'(EP) and the Struggle Phase' (SP) . The Easy Phase is defined as being up to the first diaphragm contraction (DC) and the Struggle Phase as being from the first DC up to the Break of Apnea (BA).
In our first stage of development it is very important to observe these stages: when they occur, how long they last, how many contractions one can withstand, how severe they are, and how one reacts to each phase.
There are two important subjects that are NOT included in this article:
1)Ventilation ( before either a static or dynamic breath-hold) - From experience, ventilation must be taught personally and individually to be most effective, as it involves observation and correction of technique.
2)The Mental and Psychological Aspects of Static Apnea - There simply isn't the space in this article to go into the many types of established methods that could be used to assist with this.
The Dangers!
The greatest danger is 'Shallow Water Blackout' (SWB). This is an 'hypoxic incident' that leads to a sudden loss of consciousness without any warning. When a diver's mouth and nose are submerged (as when lying face down horizontally on the surface) and he suffers a sudden loss of consciousness in this position the result is usually a drowning if he is unsupervised. Although this is very easily avoidable, it is happening with increasing frequency and there have already been several reported incidents this year. When the O2 reserves fall below a ppO2 of about 0.1 ata there is a very high risk of an hypoxic incident.
Primary Hypoxia, or the so-called 'samba', is usually associated with convulsions, trembling and an unfocussed gaze. This is commonly referred to as 'loss of motor control'.
Secondary Hypoxia, or SWB, is a sudden loss of consciousness.
'Hypoxic incidents' of varying intensity can be classified in stages from 1-3.
These stages do NOT always occur sequentially. A blackout, Stage 3, can occur without the symptoms of Stages 1 and 2 having occurred or having been observed. For example, a diver on low O2 reserves may not necessarily suffer the symptoms of a samba prior to a blackout, but may lose consciousness without any warning.
One of the dangers most touted ( particularly by ill-informed journalists )is brain damage due to prolonged breath-hold. They seem to confuse holding your breath for 4 minutes with the brain being anoxic for the same period. They are not at all the same thing! The body has remarkable adaptive mechanisms. In simple terms, the brain, which is the biggest consumer of O2, doesn't like to suffer and imposes sanctions on the rest of the body long before it suffers damage. It shuts off consciousness so the consumption of O2 by the rest of the body is reduced. When we went to Oxford University as guinea pigs in experiments involving prolonged breath-hold of 5 minutes or so, it was interesting to watch the Central Cerebral Artery dilate in response to elevated levels of CO2 and reduced levels of O2, this in order to prolong oxygenation of the brain. (Refer to the EEG graph). Also, immediately after the onset of breath-hold there is a short period of tachycardia followed by a prolonged period of bradycardia until just before the BA, and upon the BA, tachycardia again : all adaptive breath-hold reflexes.
Altogether there seems to be NO case for apnea causing brain damage.
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