Fysiology: The easy phase, the struggle phases and the break point.
By: Rik Rösken
Goal:
When you start training, and develop yourself more in to breath-hold diving,
you will be confronted sooner or later with what is known as the the 'easy phase'
and 'fight phase'. These phases have been unjustically been called "the safetynet"
of breath-hold diving, and in this article, I will explain it is instead.
What are these phases? Simple explained, the easy phase is the period of
time where your body doesn't perceive any signals during your breath-hold. The
struggle phase is the period where you do perceive these signals and have to fight mentally
or sometimes physically to stay submerged. The breakpoint is the point where you experience
your first struggle.
Often these struggles exist of what freedivers calls 'contractions'. This exists of
a rhythmic movement of the diaphram, the muscle that devides the lungs from the abdomal
organs. Your body can also struggle on various other ways, but the contractions are
the things most people are aware of.
You could think that these contractions could be a very good sign to wait for and to
hold your breath for extended periods without having the risk to black-out. People tend
to think that the loss of counciousness only happens during the struggle phase and that
it could be averted by finish your dive before that
Sadly however, that is not something to take for granted. Not every struggle sign will
present itself as a contraction. Also can the struggle phase be influeced by training and
hyperventilation, causing it to give you the wrong imperssion on your breath-hold diving
capebilities. There are also some special occasions where a black-out can occur in the first
part of the dive, this is something that will be discussed in a different article.
The main reason that the struggle phase in itself can be so illusive is that it is mostly
activated by the carbon-dioxide, the gas that is produced when burning oxygen in your body. This
gas, dissolved into your blood and other bodily liquids. While maintain your breathing pattern
under normal situations is often unproblematic, for breath-hold diving, it can be easily influenced by
hyperventilation, including the preparational breaths before diving), and many other factors like;
stress, food and air quality.The role of these gases get even more difficult when diving into depth is involved as is
explained in the article on ascent black-out. Movement, both during
dynamic and constant weight disciplines can mask struggle movements, and also for these disciplines
should the struggle phase never be used as a 'safetydevice'.
What does the struggle phase and the easy phase tell you? Well it is certainly a signal that
your body is under stress. During trainings with a qualified instructor, it can tell you imporant things
about your tollerance to oxygen, carbon-dioxide and other stressfactors in diving. When you
are aware of the struggle phase and would like to continue breath-hold diving, it is quite important
for your safety to ask the advice of a professional.
A well informed instructor can also guide you with this matter since suffering the struggle phase
on a frequent base can make you sustible for the Static Burn-Out effect
Overall, while the phases cannot be trusted for your safety, they can be quite intresting
when guided in the right fashion under the right supervision. The explanation of the instructor,
together with guided trainings can give you more insight and the experience to learn how to
work with the phases.
Sources:
P. Radermacher, C-M, Muth, Apnoetauchen - Physiology und Pathophysiologie,
Deutche Zeitschrift Für Sportmedizin, Jahrgang 53, Nr. 6 (2002).
Massimo Ferrigno en Claes E.G. Lundgren, Human Breath-Hold Diving. pg. 529 - 583.
Uit: The Lung at Depth. Volume 132. Lung Biology in Health and Disease