What is the Recovery Breath / Hook breath? How do you do it ?
The recovery breath is simply the first and most important thing to do after a dive or static breath hold. Lets start with why it is so important:
The worst thing a freediver can do after a breath hold is to exhale completely, exhaling the remainder of your O2. Exhaling with hardly any O2 left in your blood and nothing in your lungs can easily cause a samba or blackout. The reason being that a few seconds may pass before the new O2 is absorbed by the body. In fact it may be more common that divers blackout or samba 5-10 seconds after they surface than blacking out underwater. So what is the solution? The hook breath or recovery breath!
What should you do as soon as you surface?
Imagine you have pushed yourself to your limit and can’t wait to exhale the co2 in your lungs. You have just finished a deep dive and are on the way up. Last 10m, it is time to stay calm and relaxed and do not be too eager to exhale. Stay in control and upon surfacing exhale roughly 25% of your air and inhale quickly filling the remainder of your lungs making sure you keep the pressure in your lungs. This pressure is created buy closing your mouth and applying pressure from the throat, diaphragm and lung muscles. Trying to squeeze O2 back into the blood. Around 1 sec later exhale not more that 50% of your air and quickly inhale air keeping the pressure in your lungs. Hold for a second or two and repeat 3-4 times. This technique works better if they are quick small breaths rather than deep slow breaths. Keeping the pressure in the lungs not only helps to re-supply the blood with O2 but also helps to balance the changes in blood pressure, since blood pressure drops after surfacing . After I like to take a few deep relaxing breaths. Be sure to take at least double the time of your dive on the surface to recover well.
It is very important that the recovery breath is practiced on all dives, this is the only way to turn the recovery breath into a reflex action! When you push yourself to your limit and O2 is low, we tend to rely on muscle memory only, that is why the recovery breath must become a reflex action.
Always practice the recovery breath, do not let all your air out when you surface, instead exhale a little and inhale quickly again in 1 sec intervals 3-4 times and keep the lungs pressurized.