A conscious equalization is safe, efficient, and with a low energy consumption. It is important to compensate correctly to avoid squeezing in both the lungs and in the trachea.

One of the fundamental steps for an efficient equalization is the air shifting, the gesture that allows us to move the air from the lungs to the oral cavity. The air shifting can be carried out in two ways:

- The reverse packing;

- Abdominal contraction.

The reverse packing anticipates in recalling a quantity of air into the upper airways through a depression generated mainly by the downward movement of the tongue and during this gesture keeping the soft palate closed and the glottis open. The reverse packing, if carried out with the abdominal muscles completely relaxed, also allows you to reload beyond the level where the residual volume is reached.

On the other hand, the air shifting that is carried out with an abdominal contraction or expiratory effort is carried out by performing a forced exhalation in particular of the abdominal muscles. In the latter case, during air shifting, having certain precautions, the glottis and soft palate remain half closed respectively in phonation and open until the end of the maneuver, which allows bringing air into the oral and nasal cavity simultaneously.

If performed correctly, both the reverse packing and the abdominal contraction do not involve any risks of damage to the lung or the trachea.

However, one should keep in mind that the reverse packing introduces a compensatory delay that is potentially harmful to the middle ear and requires excellent awareness of all the organs involved.

Choosing one or the other is solely a function of ones goals, even if the differences are abundant beyond the quotas reached by most recreational free-divers and fishermen.

The EQ Tool, together with your instructor, is able to help you recognize both techniques and eliminate any errors during their practice for a safer and more aware approach to the sea.

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