Quite often, I start a beginner Freediving course by asking my students whether they think freediving is a dangerous activity or not. Some say yes, some say no, it is absolutely safe.
The truth is somewhere in the middle.
If you follow safety rules, Freediving is safe and enjoyable water-based activity. But if you break these rules, then Freediving becomes a Russian roulette without guaranteeing of a happy end.
And one of such rules is – don’t do hyperventilation before a breath hold!
But first of all, what is hyperventilation?
Hyperventilation is over-breathing – when you breathe more than you need to. Usually, the rate and depth of your breathing depend on a current metabolic activity (mainly on how much CO2 you produce). So, more CO2 you make – deeper or faster you breathe.
For example, when you are sleeping, you are not producing that much CO2, and your breath is shallow and quiet. But in contrast, if you are running, you create much more CO2, which dramatically affects your breathing rate and depth.
Back to Freediving. Remember, how breath-hold looks like? Relaxations breathing, breath-hold itself, and recovery breathing after.
Relaxation breathing can vary among freedivers, and we like to experiment with it. And some freedivers intentionally or unintentionally can do hyperventilation instead of relaxation breathing.
Why would someone do it intentionally? Is it an attempt to bring more O2? Unlikely, since the vast majority of O2 in your body is already connected with hemoglobin, this will not be affected by manipulation with breathing.
The answer is that someone does hyperventilation to decrease CO2 in the blood and delay the urge to breathe.
And what about unintentional hyperventilation? It can happen with a freediver who thinks that only fast breathing is hyperventilation. For example, you can hear such advice as “exhale as twice longer as inhale.” This is indeed a mild version of hyperventilation
But why is hyperventilation is not a good idea for Freedivers?
1. HR will go up. If you do deep and fast breathing, your heart rate will inevitably increase. And the heart is the muscle that requires O2. The more it works, the more O2 it consumes.
2. Lower CO2. Think about your urge to breathe as an alarm clock. When you have it, consider it a signal that you might come close to your hypoxic limit. If you remove too much CO2 by hyperventilation, you can come too close to your hypoxic limit and have a Black Out.
3. Also, removing too much CO2 will increase the blood pH level, making it alkaline. It will lead to cerebral vasoconstriction (constriction of the blood vessels in your brain), and as a result – less blood, less O2 will be delivered to the brain.
4. Hyperventilation suppresses the Bohr Effect. The presence of CO2 makes an easier O2 release from hemoglobin. If CO2 goes down, this mechanism is not working that well anymore.
Bottom line – hyperventilation should be avoided by beginner and intermediate freedivers by all means! It doesn’t give you any benefits but puts you at unnecessary risk.
More about Hyperventilation here
Stay safe!
First of all – if you are planning to train in the water, you HAVE TO have a Freediving buddy. No exception. What about easy breath holds? Still no, you have to have a buddy in any case! If no – train STA dry (less fun, but safer!).
And you want to reach 3 minutes within 3-4 months. Here is your plan (train 2-3 times per week). Choose only one of these exercises for a session
Have you noticed “PUSH HARDER” advice? No? This is because there is no such advice here! You don’t have to push harder to reach 3 minutes static breath hold!
In scuba diving, when you are breathing compressed air underwater, your body is saturated more and more with Nitrogen (79% of the air is Nitrogen). The chain looks like this – you breathe in the compressed air from a scuba tank and now the pressure of N(Nitrogen) in your lungs more than in your blood, so, it going to your blood. And now in your blood pressure of N is higher than in your tissues, so, it is going to your tissues. Until you have an equal pressure of N everywhere (this is what we call saturation). And when you start coming up, opposite happens. Now pressure of N is smaller in your lungs, so the reverse process is happening – from your tissues N going to the blood and then to your lungs and then you exhale it. But it doesn’t happen that quickly. In some tissues, this process is slower than in others.
If they violate these rules, they have a very good chance to have DCS! Without making it too complicated, DCS is when molecules of N combined in your blood (or tissues) in the form of a bubble and can cause very serious damage!
small recovery time has a very good chance to get DCS….What to do, if you are spearfisher? Limit duration of your spearfishing session, have enough rest between dives, use appropriate thermal protection, stay hydrated!
First of all – symptoms of DCS. Type 1 DCS – skin rash on shoulders and upper chest, joint and limb pain. Type 2 DCS – peripheral tingling and numbness, unconsciousness, respiratory arrest and paralysis, coughing, feeling of air-starving.
Even if you are relaxed as much as possible, you still produce some energy. And as a result, produce some CO2. And when your CO2 reaches a certain level you want to breathe (actually you want to remove excess CO2 level). In Freediving quite often we use the term “urge to breathe”. So, how are going to bring new air to your lungs? What is the process looks like?
an urge to breathe – it is simple contractions of your respiratory muscles (diaphragm for example), which are trying to remove CO2 from your body.
(only 21% is O2, 78,96% N and 0.04 is CO2) and it starts its journey into your circulatory system! There is a natural dead space (no one dies, there is just no gas exchange) on its way (nose/mouth + trachea + bronchi + bronchial), so when air reach your alveoli, it has less O2 than you when you inhale.
And within your tissues, cells use O2 for producing energy and also creating CO2 as a byproduct (as well as water). After CO2 produced, it goes to your blood (partially connected with hemoglobin, but mostly dissolved into the plasma – bicarbonate) and then going through veins to your lungs. Then again, through gas exchange, CO2 penetrates to your alveoli, going all the way up to your mouth and then you remove it through exhaling! This how we are breathing!
which cause increasing pH of your blood (blood become more alkaline – respiratory alkalosis) and it triggers Bohr effect – now a connection between hemoglobin and O2 becomes stronger and exchange between capillaries and tissues becomes harder. In simple words – even if enough O2 present in the blood, it is much harder to deliver it to tissues. Since the human brain is very sensitive to the lack of O2, as a result of hyperventilation we have symptoms – dizziness, tingling in the lips, hands or feet, headache, weakness. Or in a worst case scenario – unconsciousness (our brain simple protect us from further depleting of O2).
Maximum depth for this level is 24m. It also should be mentioned that to apply for Advanced Freediver you must get EFR first. That is also simply explained with the possible necessity to provide first aid to your buddy. And of course more advanced rescue skills should be demonstrated at this course.
Ok, snorkeling is a natural activity for us humans (especially after we invented a mask) and everyone can do it without any education.