Any advice on hyoxic training or training devices?

I'm going to climb kilimanjaro this fall, and while I don't think that the actual climb will be that bad, I've heard of a number of people crashing from altitude sickness. I live at sea level, and have concerns about this. I have been reading about hypoxic training, and some Masks. Do any experienced high altitude birds have advice or experience with this type of thing?

water water water, drink only water for the first 24 hours your there, no soda no beer no wine. keep drinking it heavly for the first couple days. Just stay hydrated, you will be fine.

Get a doctor to write you a prescription for Diamox; it really is remarkable what it does for altitude sickness.

jduby wrote:I have been reading about hypoxic training, and some training mask ...

I don't know how that particular "training mask" works, from that description in the link. More important ...
You need to be careful to understand if "hypoxic" (low oxygen) training is what you really want. Comfort and performance at altitude is more complicated than that.

Most of those hypoxic devices are purchased mainly by athletes for WADA-legal blood doping, to improve their racing + muscular performance at sea-level. Some of those devices might be tricky to use for most effective acclimatization for actual high altitude -- and many manufactures / distributors really don't know much about how to advise you to use them to train specifically for altitude (as opposed to bicycle-racing or MMA).

Acetazolamide / Diamox has been tested and used for decades -- and I've been happy with the results lots of time myself for going up quickly from sea level to a bit over 4000 meters. Note that Acetazolamide works mainly against the problem of low carbon dioxide / CO2, not low oxygen. (Another possible way to prepare for low-CO2 at altitude, is to train by breathing low-CO2 air a few days in advance).

I'm not any sort of medical professional, but what I've gotten from reading several books (remember those? made out of paper) over the years, and confirmed by my personal experience is ...
Actually many of the symptoms of Acute Mountain Sickness (AMS) are caused more by Low CO2 than Low O2. There's not much CO2 in the sea-level atmosphere, but that small amount plays a critical role in maintaining the pH balance of the blood, since CO2 dissolves in the blood as carbonic acid. So when you breathe low-CO2 air, your blood acid drops (pH rises). The pH environment is very important for many biochemical reactions, so getting it wrong is a problem for the human body, called "alkalosis" -- which results in a variety of apparently unrelated symptoms, including lethargy and nausea. The Low-CO2 aspect tends to to have a more dramatic impact than Low-O2, on enjoyment and performance at altitudes less high - (while Low-O2 becomes more important up more high, like Everest).

So even if you've done lots of Low O2 / Hypoxic training, you still might feel major symptoms of AMS while climbing to altitudes like Kilimanjaro -- because you didn't do sufficient advance preparation to deal with the Low CO2 problem.

Now for the key problem with many of the Hypoxic training devices ...
It's actually difficult and expensive at sea-level to sustain and control a micro-environment of reduced Total air pressure (too many leaks). So instead most devices reduce the Oxygen O2 and replace it with another gas, to keep the Total pressure the same as the surrounding sea-level atmosphere. The obvious alternate gas would be Nitrogen (N2) which is inert in the human respiratory system at normal or lower pressure (so it causes minimal side effects).

But directly replacing O2 with N2 is still kind of expensive, so many of the less expensive devices use an indirect approach: Re-breathe your own exhaled air. Exhaled air is low in O2. The problem is that it's high in CO2 (which tends to make you breathe faster, and at higher concentrations could get very uncomfortable, feels like suffocating). So the trick is to put the exhaled air through some chemicals (often "soda lime") which absorb CO2 and so remove it from the air. Then the normal surrounding atmosphere (which is mostly N2) comes in to replace the CO2 which was removed. If all goes well you end up breathing Low O2 / High N2 air -- on the cheap.

Then you also need to measure the oxygen / O2 levels in your blood, so in addition to the Low-O2 device, you also need to purchase a reliable "oximeter" -- otherwise your blood O2 level might either be not getting low enough to stimulate EPO and resulting O2-capacity changes, or getting so low that it's immediately dangerous.

A problem with the cheap re-breathing method is that the chemicals to remove CO2 get used up -- so as you keep using the cheap device, less CO2 gets removed, so after a while you're breathing Low O2 / High CO2 air instead of High N2 air. So you have to replace the chemicals, which you have to purchase from somewhere, in some form or container that you can easily get into your device. Presumably the manufacturer / distributor of your device will gladly sell it to you -- which substantially changes your cost calculation.

The bigger problem is that there's no cheap way to measure the concentration of CO2 in the air you're breathing (or in your blood) -- so you don't know how rapidly the CO2-removal chemicals are depleting. Therefore with the cheaper devices you are breathing air with ...
uncontrolled (and changing) concentrations of CO2
(Which impacts blood pH. Which is real important)

Gotta be real careful playing games with blood gases ...
Medical professional use the "soda lime" trick all the time, but they have the expensive devices for accurately measuring the CO2 concentration they're producing.

warning 2: Most forms of successful Hypoxic / low-O2 training increase the risk of blood clots / embolisms - (getting one is real bad) - like injecting EPO. Consider taking preventive measures on long airline flights (or car or train rides?) to and from your climbing location. Seems to me it would also be smart to have your blood characteristics measured before trying any hypoxic training -- some people have blood which is already fairly "thick" in RBC -- or other factors that pre-dispose to embolisms.

Low CO2 training ...
If do not feel any need for hypoxic / Low-O2 training (with its higher cost and embolism risk), you can breathe Low-CO2 air just by passing normal sea-level air through "soda lime" or other CO2-removing chemicals -- without any re-breathing. Since the concentration of CO2 in the normal atmosphere is much lower than in exhaled air, the chemicals should last a lot longer before getting depleted. Again ...
Low-CO2 air is serious stuff. First time I tried a Low-CO2 session I overdid it and felt almost "knocked out" for like three hours afterward. I think basically I induced intense AMS symptoms. If trying it at all, start with very short exposure periods.

Acetazolamide / Diamox is better understood, less risk, takes less time, for me less discomfort, than low-CO2 training sessions - (but still sometimes I use Low-CO2 sessions together with Acetazolamide).

If you do Hypoxic training with the cheap re-breathing method, and you replace the CO2-removing chemicals frequently, then I'd thing you're also getting some reasonable low-CO2 training. But if you use an expensive Hypoxic training device (with direct replacement of O2 by N2), then likely you're not getting much low-CO2 preparation spcific for altitude.

Be glad to get corrections and suggestions from those who know better.

Ken

kilamanjaro doesnt involve any climbing...

Thanks for the advice everyone.

superkick wrote:kilamanjaro doesnt involve any climbing...

Doesn't sound like advice to me.

Just sayin, Kili..hiking...Kili...hiking

Yes, the lower partial pressure of atmospheric O2 is the underlying cause. Genetics, your mitochondria, and glycolytic pathway also play a role.

Nothing is going to trump taking the time to acclimatize in the actual high altitude environment.
Trying to screw with your respiratory buffer at sea level without physician involvement isn't something I would do.

Diamox is a good renal tool that will allow you to pee off bicarb and help keep you mitigating alkalosis when at that environment and provided days prior to high altitude exposure/summit attempt. In your home environment, the danger could be putting into acidosis.

You'll pee alot. So water is good. Not so much related to an altitude illness, but using water to keep up with fluid loss. Manage your electrolytes also.

NSAIDs are also showing helpful, but should be reviewed based on your history. Endurance athletes run into rhabdo trouble with them.

You can also ask about ED meds, but for the pulmonary hypertension; which was their original design.

Steroids should be avoided unless for an emergency to help get you down, thus not a climbing tool.

As far as training, just maintain a healthy diet and physical fitness. Prepare with a viable packweight (don't take too much crap), and allow adequate time in your schedule to adjust to the environment.

So far have never done anything other than garlic and aspirin at altitude myself but Diamox is great for particularly base AMS for sure. As far as training goes, I trained for 20,000+ feet living at near sea level in Delaware before. Really what it comes down to is your genetic disposition to AMS or not and really (probably 90%) your training. Do lots (LOTS) of interval training and many types of cardio cross training. I would do stair master, elliptical, rowing and running and of course as much hiking as possible with a heavy pack full of jugs of water. Then do even more cardio with a pack. Slowly increase the weight on that until you can with 35lbs what made you want to puke with body weight. Drink tons of water while training and during travel and first days there and the whole trip actually. You should be fine.

I think this is what you're looking for.

Fix firmly over head with tape and train away.

jduby wrote:I'm going to climb kilimanjaro this fall, and while I don't think that the actual climb will be that bad, I've heard of a number of people crashing from altitude sickness. I live at sea level, and have concerns about this. I have been reading about hypoxic training, and some Masks. Do any experienced high altitude birds have advice or experience with this type of thing?

Buff has offered good advice.

Hypoxic training and resistance masks purport to improve general fitness but I would not expect them to have any beneficial influence on altitude sickness. I doubt they help aerobic fitness either, but am somewhat jaded. There were some european climbers that prepared for himalayan trips by using altitude tents, but I haven't heard about anyone doing that for years, so doubt they helped.

It would be hard to be against doing as much aerobic training as you can before you go, but I don't think you need to train till you puke, or practice carrying heavy rucksacks, unless you plan to compete with the porters.

Altitude sickness is a concern on Kili, the best preventative measure would be to add an extra day or two to your ascent (take one of the longer routes maybe?)
Diamox is safe and helps many people if used prophylactically. You may want to try a trial dose at home before you go just to make sure you can tolerate the side effects (no beer and tingling fingers.) Check with your Doc first of course.
While talking with your Doc, get his/her advice about other altitude meds and a prescription for whatever you decide to take along.

Whatever you do, don't take high dose decadron for weeks on end a la the unfortunate Everest climber profiled in Outside magazine!
outsideonline.com/fitness/C…

Here's an online article that might help explain the options-
wwwnc.cdc.gov/travel/yellow…

Have fun! Hoping to get to Tanzania with the family in the next couple of years.

Buff Johnson wrote:
> "Yes, the lower partial pressure of atmospheric O2 is the underlying cause"
... and ...
> "Diamox is a good renal tool that will allow you to pee off bicarb
> and help keep you mitigating alkalosis"

But if Low partial pressure O2 is supposed to be the big problem, then how would taking Diamox and urinating bicarbonate help?
Seems to me "bicarbonate" is something about Low CO2 not Low O2.

Ken

Mark E Dixon wrote:
> "some european climbers prepared for himalayan trips by using altitude tents,
> but I haven't heard about anyone doing that for years, so doubt they helped."

I recall that a U.S.Army study in the last ten years also found that Low O2 exposure in advance did not help with performance at altitude.

But if Low O2 actually were the big problem with climbing at altitude, then getting hypoxic exposure in advance by sleeping in an altitude tent should help.

Altitude tents for hypoxic exposure typically use the more expensive approach of replacing O2 directly with N2, without changing CO2. That doesn't help the Low partial pressure CO2 problem, so it doesn't do much to prevent Acute Mountain Sickness (AMS).

Mark E Dixon wrote:
> "Diamox is safe and helps many people if used prophylactically."

Diamox / acetazolamide does impact CO2 / bicarbonate in the bloodstream so it does help prevent AMS.

For me, once I understand AMS as mainly a problem with Low CO2 and resulting alkalosis, everything makes sense.

Ken

kenr wrote:Mark E Dixon wrote: > "some european climbers prepared for himalayan trips by using altitude tents, > but I haven't heard about anyone doing that for years, so doubt they helped." I recall that a U.S.Army study in the last ten years also found that Low O2 exposure in advance did not help with performance at altitude. But if Low O2 actually were the big problem with climbing at altitude, then getting hypoxic exposure in advance by sleeping in an altitude tent should help. Altitude tents for hypoxic exposure typically use the more expensive approach of replacing O2 directly with N2, without changing CO2. That doesn't help the Low partial pressure CO2 problem, so it doesn't do much to prevent Acute Mountain Sickness (AMS). Mark E Dixon wrote: > "Diamox is safe and helps many people if used prophylactically." Diamox / acetazolamide does impact CO2 / bicarbonate in the bloodstream so it does help prevent AMS. For me, once I understand AMS as mainly a problem with Low CO2 and resulting alkalosis, everything makes sense. Ken

Here's a reference that might help explain things-
sciencedirect.com/science/a…

The exact cause of altitude illness is still a subject of research, but seems to be related to low oxygen levels rather than changes in CO2.

The neurologic control of breathing varies between people too, and there have been theories that people who have more of a hypoxic drive to breathe (that is, their mind drives them to breath to maintain a certain oxygen level) have less altitude illness than folks who have more of a ventilatory drive (that is, their mind wants to maintain a certain level of carbon dioxide.) Diamox may influence the balance of hypoxic vs ventilatory drive in a beneficial way. Or it may work in an entirely unexpected fashion!

It does seem like controlled pre-trip hypoxia should work, but AFAIK, it has't. Maybe the obligatory time spent at lower altitudes in transit eliminates the benefit, or maybe nobody has found the right formula. I wouldn't spend my time/money on it personally, would just ascend at a reasonable rate and hope for the best.

Mark E Dixon wrote:
> "Diamox may influence the balance of hypoxic vs ventilatory drive
> in a beneficial way. Or it may work in an entirely unexpected fashion!"

But acetazolamide / Diamox has been well-studied and widely prescribed for decades. So it's rather clear how it works: by regulating blood alkalinity and bicarbonate (which is directly connected to CO2 dissolved in the blood, which is directly related to partial pressure of CO2 of air in the lungs). See the fourth paragraph of Buff Johnson's post above.

Of course in that way Diamox does influence ventilatory drive, since concentration of dissolved CO2 in the blood and resulting rise in alkalinity is an important driver of ventilation / urge to breathe.

Mark E Dixon wrote:
> "Here's a reference that might help explain things-
> sciencedirect.com/science/a…

But that article on "High Altitude Illness" by Basnyat and Murdoch is mainly about High altitude, like over 6000 meters - (the article opens with stories about Everest). It is only interested in the more extreme forms of AMS and lots more about HACE + HAPE -- not the usual symptoms lots of us experience at moderate (Kilimanjaro is below 6000 meters) or low altitudes. The article says that their concern "encompasses the mainly cerebral syndromes of Acute Mountain Sickness". In the second page, their Pathophysiology of AMS is mainly about "brain swelling".

Diamox? The article mentions several possible drugs, but not acetazolamide -- I would guess because ot is not interested in the non-extreme non-cerebral symptoms for which acetazolamide is most helpful.

In my first post above I did say that Low CO2 was the main driver for "many" symptoms of AMS at "altitudes less high". I gladly acknowledge that Low O2 (and low Total pressure) are important at high altitudes over 6000 meters.

Ken

kenr wrote:In my first post above I did say that Low CO2 was the main driver for "many" symptoms of AMS at "altitudes less high". Ken

Do you have any scientific evidence for this? Please share if so.

AFAIK, there is no difference between altitude illness at 4000 meters, 6000 meters or 8000 meters.

Ken, I wouldn't draw a magic line between moderately high, very high, or extremely high altitudes with respect to altitude illnesses. We've seen cases of hape and hace at around 3,000 meters. If we had hotels on the tops of ski areas, we'd have even more.

Trying to figure out CO2 when the bigger picture is lower partial pressure O2 seems like splitting hairs to me. There are also studies looking at the partial pressure of water. It's still low partial pressure of O2 in the environment that will lead to tissue hypoxia.

Diamox allows a pH adjustment to occur quicker by allowing the renal system to dump bicarb. You still have to adjust mitochondria through its genetic process, and shift the Hb bond curve in the glycolytic pathway so that it won't hold onto oxygen as tightly as it does.

You still need days in adjustment in that environment.

EMed also has a good breakdown of describing Altitude Illness.

Mark E Dixon wrote: Do you have any scientific evidence for this? Please share if so.

My evidence is that Diamox / acetazolamide works for preventing and treating many symptoms of AMS, and Acetazolamide obviously impacts the human body's utilization of CO2.
(Also for me personally, intermittent exposure to breathing Low-CO2 air by means of soda lime treatment seems to work to enable me to perform much better on my first day up at altitude from living at sea-level).

More evidence: The U.S.Army study which found that advance exposure to Low-Oxygen (with normal-pressure CO2) did not work.

Do you have any scientific evidence that Low partial pressure of Oxygen is a major driver for most of the non-extreme non-cerebral symptoms of AMS? Please share if so.

Do you have any scientific explanation for how Acetazolamide has much affect on the biochemistry of oxygen utilization in the human body? (other than by indirectly influencing the urge to breathe)

Back fifty years ago when smart scientists were studying altitude, there were thousands of possible drugs which could have been tried to prevent or mitigate many of the symptoms of AMS. If those smart scientists had believed that the main driver of those symptoms of AMS
was low partial pressure of Oxygen, how would it ever have occurred to them to select Acetazolamide as the one to seriously test?

Ken

Buff Johnson wrote:
> "I wouldn't draw a magic line between moderately high, very high, or extremely high altitudes
> with respect to altitude illnesses. We've seen cases of hape and hace at around 3,000 meters."

Good point.
So HAPE + HACE are surely serious concerns for a trip on Kilimanjaro.
And I'm not suggesting that advance use of Acetazolamide or Low-CO2 exposure sessions will help prevent cerebral swelling or HACE or HAPE.

A possible danger of taking Diamox / acetazolamide in advance is that the resulting reduction in non-extreme AMS "discomfort" symptoms will encourage a climber to progress too rapidly to higher altitudes, and then run into really serious trouble with HAPE or HACE.

Ken

Ken, I'm going to need to gracefully withdraw from this discussion.
I feel competent offering standard advice on preventing AMS to jduby who can consider it or ignore it as he/she sees fit.
I claim no special expertise in the pathophysiology of altitude illness. There is plenty of good research available and if this is genuinely an area of interest for you, I think you would get more from reading the primary sources than from reading my interpretations.

no beer no wine...no beer no wine...no beer no wine...

Thanks for the great responses everyone. I've learned a lot thanks to you all. I do a lot of hiking, but this will be my first hi-altitude climb, so I have a lot of questions. Do any of you know about blood oxygen meters? Are these a worthwhile investment for high altitude climbing?