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Switching to anaerobic process

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100 % H2O
Feb 5, 2002
My theory is as such.

Whilst slow and relaxed are critical for the first half of my dive...

I have found that when diving the second half of a dive ( ascent) or the second half of a dynamic ie. (someplace after the first turn ) if i speed up considerably, the urge to breathe dissapears and my performance increases. I get more distance in dynamic and in constant i surface ( perhaps more physically pooped ) but way more solidly (consciously) than if i maintain a slow pace or even slow down to preserve air and relax more.

Perhaps this is why i have a fondness for stiff fins or even a stiff mono because at the turn when i 'bust loose' i put a loading on my legs, get a reduction in a urge to breathe, the psychological boost of the rope flying past me and the knowledge that the surface is approaching at relative warp speed. This is not a panicked ascent but rather a steady rhythmic faster beating for the surface. I also only get this effect when breaking into a dolphin kick.

I use the softest rubber hockey fins for dynamic though because i cannot perform the first half of the dynamic slow and relaxed with a stiff mono. ( i can still descend in constant slow and relaxed with a stiff mono.)

I take it that the first part of a dive is aerobic and i believe it is mostly as a result of the momentum of the aerobic process we use to produce the trickle of energy needed to keep our bodies running at low level. The descent is not too stressful and should not invoke the anaerobic process too quickly.

Anaerobic processes take over when a body is called upon to perform a burst of hard work. Like when you alternate jogging and sprinting or when you kick hard when turning at depth.

Could their be a basis for my theory, that , when kicking hard i switch from aerobic to anaerobic processes positively and no longer consume oxygen in my blood for energy but start burning up ATP stores in the muscles thereby preserving oxygen in the blood for consumption in the brain prolonging consciousness and comfort ?

Something similar happens to me...

Im at 12fsw holding my breath. About a minute and a half I get my first "urge" to breathe. (keep in mind that im still a newbie). I slowly kick off of the bottom and bring myself up to about 8 feet where the urge disappears. Two minutes and I am getting an urge again. I start kicking forwards, and the urge disappears after a few seconds, and I can generally last about 30 seconds more.

Something to think about. I reasoned that I was concentrating on kicking and not on the urge.

I think you're right on the mark. Although, during the anaerobic phase, you are first consuming ATP/CP then glycogen+glucose which produces the acid.

Your description is an example of why I always sprint to the surface on deep dives, even though I descend very slowly. Sprinting also reduces the time in the 'death zone' above 15m where you suffer the vacuum effect as each heartbeat causes blood to deoxygenate as it passes the lungs. In a sense, you 'escape' shallow water blackout by passing through the death zone too fast. This is in addition to the other effects you mentioned.

Eric Fattah
BC, Canada
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Eric, could you reprise the short story on anaerobic vs aerobic chemistry in the muscle tissues, and why it is that the anaerobic
process is so damned tiring ? This ought to be something you can
cut and paste from your files, and it is worth repeating often. Plus,
I know a certain reader of this space who is keenly interested, and I can't remember the details.


Paul Kotik
My understanding of the metabolic sequence during an apnea:

1. You hold your breath
2. You start moving
3. Muscles initially burn the ATP stored in them
4. Within a fraction of a second the depleted ATP is regenerated by buring creatine phosphate (CP)
5. Within a fraction of a second after that, the creatine phosphate begins to regenerate from O2 stolen from the myoglobin in the muscles, but this process is somewhat slow and can't keep up
6. Several seconds later, the muscle begins to burn glycogen (stored in the muscle) and glucose (mainly from the blood). This reaction always produces lactic acid, but assuming that enough O2 is available from the blood & myoglobin, the lactic acid itself is converted to energy; this reaction produces CO2, water and energy as its byproducts (this 'completed' reaction is called aerobic metabolism, as opposed to the incomplete reaction which is called 'anaerobic').
7. Eventually, the O2 supply declines, replaced by CO2.
8. As the O2 supply declines, both the lung O2 decreases and the blood O2 decreases.
9. The myoglobin relies on the blood to replenish its oxygen, but as the blood becomes less oxygenated there is less and less O2 fed to the myoglobin.
10. The total O2 in the muscle from myglobin & blood now decreases, and not all the lactic acid from the [glyocogen+glucose] reaction can be converted into CO2, water and energy, so the lactic acid begins to acculumate in the muscle.
11. Because the O2 flow to the muscle is slowing down, if the athlete slows his effort to a crawl, the lactic acid can indeed be converted to energy, CO2 and water, despite the slow flow of O2.
12. If the athlete accelerates his energy production, then there is no hope to clear the lactic acid (due to the slowed O2 flow), and the lactic acid accumulates rapidly (in both the muscle AND the blood).
13. As the lactic acid accumulates, the muscle tissue itself becomes more acidic (i.e. pH decreases), which inhibits many enzymes responsible in the reactions which generate energy.
14. Due to the inhibition of these enzymes, the reaction rate of [glycogen+glucose] is further slowed, and the muscle begins to fatigue rapidly (the definition of fatigue is reduced power output which is what happens when the enzymes are inhibited)
15. Additionally, there is some sort of sensor mechanism which converts the pH in the muscle to a sensation of burning.
16. If effort continues, and O2 supply does not improve, eventually the pH in the muscle drops so low that the muscle fails entirely.
17. When O2 supply is resumed, the lactic acid will be cleared, then the creatine phosphate, ATP and myoglobin will be regenerated, and function returns to normal.
18. The more lactic acid which waits to be cleared, the greater the 'oxygen debt' of the athlete, and the longer it will take to recover after the apnea.

Some creatures can escape this cycle. The crucian carp can live on entirely anaerobic metabolism for three months, without a single molecule of oxygen. Although the crucian carp would like to clear out the lactic acid with oxygen, if oxygen is not available then it can convert the lactic acid to ethanol (alcohol), which it then excretes through its skin. Researchers often put crucian carps in small bowls, in deoxygenated water, and sure enough the water itself starts to get saturated with alcohol as the carp eliminates its lactic acid by converting it to ethanol and then 'sweating out the alcohol.'

After about three months, the crucian carp simply runs out of fuel (glycogen = carbohydrate), and it eventually dies.

Eric Fattah
BC, Canada
Hi Skindiver,

I have the same aproach as you to dynamics, and depth diving, and it works well for me too. In a max dynamic I do the first lap fairly slow, relaxed flutter kick. Second lap I change to a dolphin kick and speed up, then after the 100m turn I almost sprint. I always thought it worked for the reasons you and Eric explained.
The lactic acid build up is pretty bad at the end though. :D

Depth diving is similar although I kick quite hard the first 20m going down to build up momentum, then ease off, and kick hard again going all the way up. I often switch to a dolphin kick half way up when my legs start wearing out.

I also like using really stiff Bi-fins. I have used a monofin a few times for dynamics but need more practise. I'm getting a monofin real soon so will start trying it out for depth diving also.

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Eric, I thank you. That is a concise and useful account.

What do you think about popping some vitamins E and C shortly
before or after an intense apnea session ? I've heard that
some folks believe these and other antioxidants help speed up
the cleanup and recovery.
I strongly recommend taking lots of antioxidants during periods of hard training, especially if your training involves profound hypoxia (such as max effort apnea). A good load of antioxidants immediately afterwards, and some hours before, really does help. If you overtrain hard apnea, you may find your thinking processes slowing down the next day, although this may take weeks of overtraining to notice. Taking extra antioxidants can slow or prevent this from happening.

There are an IMMENSE number of antioxidants, for example:
Vit C
Vit E
n-acetyl-cysteine (precursor to body's own glutathione)
Alpha Lipoic Acid

Each color pigment in fruits/veggies:
Purple #2: Proanthocyanidin (grape skin / grape seed, others)
Purple #1: Anthocyanidin (blueberries, bilberries, purple cabbage etc.)
Blue: Phycocyanin (various)
Red: Lycopene (i.e. tomatoes, red peppers, etc..)
Green: Chlorophyll (dark green vegetables)
Yellow: ?? (yellow peppers etc.)

Plus, an immense number of other phytochemical antioxidants, such as:
quercetin (mainly in citrus & spinach)
dihydroquercetin (rare)
(also other bioflavonoids under the skin of citrus fruits)

So, a diet high in raw fruits & veggies, along with some antioxidant supplements, will do wonders for preventing damage from too much apnea. Making yourself a liter of fresh grapefruit juice, or spinach juice, or any fruit/veggie juice will contain TONS of antioxidants, but you must drink it immediately after you make it. Store bought fruit/veggie juices have very little antioxidant power left in them.

Eating lots of cooked, processed or junk food also produces oxidative stress, so you might want to minimize these during hard training, or all your antioxidants will just be used up in neutralizing damage from your diet (and/or environment, pollution, etc.)

Only a few years ago I couldn't do hard apnea without noticing side effects of slowed thinking. Now, with a full antioxidant load and a modified diet, I can have several sambas per day without noticeable side effects, although that still doesn't mean that no damage is occurring, and I don't recommend sambas.

Eric Fattah
BC, Canada
Don't forget my favorite anti-oxidants: red wine (a very good one) and black or green tea.

You can also get red wine antioxidants extracted out of the red wine into capsules, without the alcohol... You can get olive oil/leaf antioxidants extracted into capsules.... hell if you took every antioxidant in capsules on the market, you'd be taking 300 capsules per serving.

Eric Fattah
BC, Canada
Hi Guys,

I find your approach to the effort given during your dynamic and CB interesting. I was always under the impression that keeping kick cycles slow and gentle was the best way to maximize time/depth.

Would you guys mind givng an example of a CB dive? For example, how hard would you kick when you start descent through to the end of your ascent and the changes you make throughout.

Thanks for your info.

Jason Billows
Ottawa, Canada
What about buffering the lactics acid produced as a result of anaerobic processes

involved in training.

Have you tried taking sodium bicarbonate or sodium phosphate?

I never tried any of these chemical compounds yet, but I wanna give it a go now since apnea is really giving me lots of trigger points plus the gym work I do.

regards, gerard.
I forgot

because I train intensively and because I have high muscle mass in a thin body structure I'll be producing more lactic acid than a leaner athlete in terms of muscle mass.

I fear using sodium bicarbonate due to the fact that it will jack up my sodium levels incredibly, therefore the risk of high blood pressure which is not desirable when training hard. And taking only one teaspoon I reckon is not enough to provide you with the goodies.

Sodium phosphate is effective but research recommends around 3.5-4 gr per day to get the goodies which are: improved V02 max of 9%, LT raised by 12% and blood-haemoglobin levels by 5%. and with the local prices (Brisbane) of this product, around $10 per bottle, that in turn will last me 3-4 days. That is $20 bucks per week or $960 per year just for a bloody supplement.

What do I do? Help folks?????:waterwork

Regards, gerard.
I have tried all the bicarbonate/phosphate/citrate loading, and I recommend against it. Stomach upset, nausea & diarrhea are constant problems. Herbert tried it, and he may have even used it on his 181m dynamic record (remember he complained of diarrhea!)

You can get them for cheap from food grade chemical suppliers (which is what I did), and you can use combinations of say 3:1 sodium phosphate to potassium phosphate etc., to keep your electrolytes relatively balanced, but in the end, the result has never been very good. It seems to throw the body off.

The best way to improve your anaerobic/acid threshold is simply to train anaerobically!

Eric Fattah
BC, Canada
Hey there Skindiver

Just something to add to what you have said, during my training sessions lately, I have been doing quite a few dynamics. Towards the end of my session to really get the benefits of my work, I begin my dynamic with a static, starting at 30secs and buidling up from there and after the static I move into a dynamic swim. The static begins to get really hard as you push the times up but I really break out in speed with my mono into a dynamic and I feel a relief. I start to get contractions and feel really uncomfortable towards the end of my static to the point where I fel I cannot go on and as soon as I burst out in speed for my dynamic, the contractions and feeling of discomfort disappear.
So maybe there is method in your madness of creating a wake in the pool.

See ya around.....when you coming to train with us ?????
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Aerobic and anaerobic

I agree with Skindiver, and Eric explain very well the process, but there are something flying in my mind.
When we are doing apnea, the oxygen compsumtion is lower than in rest (at least in static apnea) but it has to be a little higher in dynamic or in the up-phase of constant. But we have arterial constriction, so the blood flow in the muscle is below normal. I think the muscle cell has to relly on local oxygen and substrates to generate energy. Thats why the blood Oxygen is less important than the cell oxygen (myoglobin). Due to the high ambient pressure we are hyperoxic at descent and bottom, so this part has to be aerobic. But in ascent we increase the metabolic demand of the cell, and as we ascent the Oxygen availabilty is lower, thats the moment when we need to generate energy in the anaerobic way. The CO2 production to the blood is lower than usual and also we can have reverse transfer in the lungs, thats why the CO2 in the first exhalation of a freediver is lower than expected, it remains in the cell.
I think we all have to train both aerobic and anaerobically. What is the best training? Freediving
Will other exercises be helpful?
My experience is that if you are ascending from a depth of around < 55m, the hyperoxic blood still flows into the muscle, and so your muscles consume a lot of O2 aerobically on the ascent. However, when ascending from 65m+, the blood shift is strong enough that despite super high O2 in the blood, very little blood gets into the muscles, and the beginning of the ascent is mainly anaerobic. When ascending from 80m+, blood flow to the legs is virtually cut off, resulting in leg fatigue very early on the ascent.

Of course, the actual depths will vary from person to person based on rib cage flexibility and magnitude of blood shift; my point is that the deeper you go, the more anaerobic the start of the ascent becomes.

Eric Fattah
BC, Canada
Anaerobic threshold

Yes, but you are a highly trained freediver. I think that the "anaerobic threshold" is different for every freediver. We have different muscle cell types and the compositions can vary widely. I think the kind of training can affect this too.
I made some cardio-pulmonary exercise test to a group of mountain climbers, that train under hypoxic conditions (they run up-hill at 4000 meters over sea level) 2-3 hours. And their anaerobic threshold was very early, and their exercise was around 120% of predicted VO2 Max.
Thanks Eric

but what I want to is neutralise the negative post-effects of lactic acid.

Regards, gerard.
In my experience, the best way to eliminate any negative effects of lactic acid after exercise is to do 30 minutes of slow cardio. Increased blood flow clears away waste products. I think the worst thing to do is to just stop the exercise and rest, leaving all the acid and wastes in the muscle.

Trevor Hutton used to do sets of 60m dives where he would swim for 5-7 minutes in between each dive to clear the acid, then breathe for 5 minutes, dive, swim, breathe, dive, etc., and this could be kept up forever because the waste products were cleared.

Eric Fattah
BC, Canada
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