Use of the Altium i10 for Intermittent Hypoxic Training

The Altium i10 is a portable, power-free device that is designed for bouts of intermittent hypoxic training (IHT). Technically, it is normobaric intermittent hypoxia, which means that the barometric pressure is unchanged from sea level (unlike at altitude, where barometric pressure is lower), and it's simply the available oxygen levels that are decreased. The effect of barometric pressure is beyond the scope of this article, except to simply acknowledge that it may be an important factor in altitude training.

To use the Altium i10, you breathe into - and back out of - an adjustable volume chamber that's also adjustable in how much air easily turns over in that chamber. Through your body's own metabolism, this process reduces the amount of oxygen in the air you breathe. But unlike breathing into and out of a paper bag, it uses a CO2-scrubbing compound to remove CO2 from exhaled air, which makes it possible to conduct prolonged sessions.

It's an excess of CO2 - rather than a lack of oxygen - that leads people to feel sick when doing something like bag-breathing, which is why CO2 scrubbing is essential. Your body will respond and adapt to reduced amounts of oxygen. You will not adapt to breathing in an excess of CO2.

Intermittent hypoxic training - in which you drop your SpO2 (saturation percentage of oxygen) in your blood down as low as 80%, which simulates the altitude of elevations as high as 20,000ft+ - is purported to offer many of the same benefits of "real" altitude training in a much more time efficient manner.

Products like this are extremely hard to evaluate thoroughly and scientifically outside of a controlled trial, but long-time altitude resident and Slowtwitch Winter Sports Editor Jon Schafer, who splits time between Steamboat Springs, CO (elevation 7,250ft) and Philadelphia, PA, and I put the Altium i10 through its paces to see what we could - and could not - learn about the promises it makes and how well it delivers on them.

Altitude No Longer As In Vogue

The use of altitude training to benefit endurance performance is certainly not new, but it seems to have largely fallen out of vogue in recent years. When I first started racing (way back in 2003), I remember athletes sleeping in altitude tents, doing regular camps at altitude (I did quite a few in Flagstaff, AZ - elevation of approximately 7,000ft), and even using hypoxic "chambers" to train. Hypoxico and CAT (Colorado Altitude Training) were companies that most athletes seemed to know, with near ubiquitous ads in Triathlete and Inside Tri.

While the thin air of Boulder certainly remains popular for triathletes, altitude is certainly less in vogue than it was a 15-20 years ago. Why is that? In large part, I think it's because altitude "science" made promises that never really lived up to the hype. If you believed the science, no one could be competitive without training at altitude. The purported gains were simply too massive.

Yet in both my own experience and as reflected in the performance of countless world record setters, Olympic medalists, and world champions, altitude was clearly not only non-essential, it was also something fraught with risk. It's very easy to get sick at altitude. And once you get sick, you stay sick. It's harder to do speed-work. And while altitude certainly can have a positive impact on your blood profile, it's just not clear that the limiter for most athletes is the amount of oxygen your blood can carry; it's more of how much oxygen your muscles can actually use.

I'm of the opinion that a lot of the research on altitude training was simply a cover for doping. In much the same way that everyone was, for a while, fixated on cycling cadence and "efficiency," (c.f. the now-discredited Ed Coyle paper on Lance Armstrong). Certainly I wouldn't say that all research was intended as mis-direction - certainly I know scientists who truly believed (and believe) the research that was done, but certainly I think some of it was just a plausible story.

Altitude training does naturally stimulate the production of endogenous EPO. So it's a nice way to cover up actual EPO usage. It's interesting to look back at some of concerns within the then-burgeoning industry about potential WADA regulation of altitude tents. That threat never materialized. But altitude training nevertheless fell out of favor, presumably because - as with most products that over-promise and under-deliver - the results simply were not there.

However, having spent time at altitude, it's clear that it does something. Ultimately, I believe that altitude is simply a stress on the body. And, for athletes going to altitude camps, it can be a novel stress that - when managed correctly - can force adaptations. I certainly no longer believe altitude training is essential, but that doesn't mean it isn't useful.

Altitude as a Specific Stress... For Racing at Altitude

Altitude training is unquestionably necessary in one instance - you plan to race at altitude. In the case of racing at altitude, altitude training no longer becomes a general stress on the body, it becomes a specific one. If you are planning to race at altitude, you need to train your body to respond to the specific demands of reduced environmental oxygen.

You can certainly make the argument for selection bias in the cases of athletes who live at altitude when competing at sea level - athletes who live in a high-altitude environment explicitly for the training benefit are more likely to be more serious about training, and it's that - their seriousness about training - rather than altitude that makes a difference.

But for races at altitude, the results are simply too overwhelming. It's clear that you just cannot be competitive in a race at altitude without training at altitude. In the case where there is fundamentally not enough oxygen for your muscles, you need to force adaptation to that specific stressor.

Altitude as a General Stress

For races at sea level (or even moderate altitude - say, a race like Calgary, CAN at 4,000ft or so of elevation), you can clearly prepare without needing to train at altitude.  At lower elevations, where the lack of environmental oxygen is not the primary performance limiter, it's just not clear that being able to transport more O2 to your muscles is going to offer a real performance benefit.

Altitude still places stress on your system. This is not inherently beneficial, but it can be. Just like training is the heat is absolutely necessary for racing in hot weather but can also offer a benefit in temperate environment, likewise altitude can stimulate positive adaptations. I wouldn't say that this stress is worth trading for the most important specific stresses. I.e., altitude is only good if you add (approximately) it to your swim, bike, and run, not when you hope to replace some of that training with training at altitude. In other words, altitude is useful when it allows you to increase training load, and it's detrimental when you end up needing to reduce it, as can easily happen.

Existing Research on Intermittent Hypoxic Training

Altium supported their own study in 2015, available here, conducted by Dr. Chris Easton BSc, PhD, PGCHE, FHEA a Senior Lecturer at the University of the West of Scotland . The findings are compelling from the standpoint of physiological metrics, but as discussed above, they aren't actually findings of performance improvement. Per the study,

The increases in VO2max following the IHT protocol are likely to be of substantial benefit to endurance athletes although the precise performance gain cannot be ascertained on the basis of this measurement alone. [emphasis added]


These physiological adaptations would provide an approximate performance advantage of over 2 minutes over a 20 mile time trial.

The study shows that use of the Altium i10 for IHT has statistically significant positive impacts on VO2Max and wattage at VO2Max, but it seemed - interestingly - to have a negative (though not significant) impact on hemoglobin and no affect on hematocrit, leading Dr. Easton to conclude,

There were no changes to blood parameters following IHT suggesting the improvements we are observing are due to beneficial physiological adaptations of the muscles.

There's also the issue here that the study contained only 18 participants, and that of those 18, five did not complete the study. 13 people is simply not a lot. Further, this was not a controlled study. All participants used the device during the trial. Taken in total, I do not find this study particularly persuasive.

But what about prior research on IHT? At least one study showed positive metabolic adaptations for athletes - supporting Dr. Easton's conclusion that the improvements are not related to blood parameters but rather to adaptation of the muscle, something that I think also emphasizes the idea that altitude training is beneficial precisely because it's a stress rather than because the ability to transport more oxygen is a benefit. Research on mice also indicates that the changes are metabolic in nature.

Altium i10 as a General Stressor

My own experience with the Altium supports the idea that IHT impacts metabolism. I would struggle to quantify any sort of performance change, especially given that I "tested" the unit during the transition from off-season to pre-season, when my fitness was skyrocketing anyway. But I did notice a very definitive affect on my metabolism, which we'll discuss further below. I would hesitate to describe this as either positive or negative, but I would at least say that I agree that the Altium i10 does something.

Is that productive? I don't know. I can see it going both ways. If you are struggling to lose weight, increasing your metabolism can be helpful. But if you are struggling, as athletes during heavy endurance training can, with simply getting enough calories, do you really want to add to your metabolic load?

Altium i10 as a Specific Stressor

If IHT seems to primarily - or even exclusively - impact metabolism, this raises an interesting question - Can you pre-acclimatize to altitude with the Altium?

A 2014 study set out to examine this question, with favorable results,

These results suggest that moderate to heavy intensity IHT provides a mean of improving the capacity for submaximal exercise and may be useful for pre-acclimatization for subsequent exercise in hypoxia, but additional research is required to establish its efficacy for athletic performance at sea level.

For our purposes, this is arguably the most interesting use of the Altium - allowing sea-level-based athletes to effectively compete at altitude, but also the most difficult to test either with a personal evaluation (it simply wasn't pragmatic nor scientifically robust to make a trip to altitude without using the Altium in advance and then using it in advance) or with limited numbers of participants.

Limitations of Evaluation Methodology

The ideal methodology for testing a device like this would involve a reasonably large group of athletes. It's not impossible to "blind" athletes with a device like the Altium, though it would present a challenge. But really there are two particular questions, and each needs to be answered via a different testing methodology.

Device Set-Up

We both received initial instruction on both set-up and usage and yet still struggled. A second, follow-up one-on-one consultation was necessary to get both of us going. This seemed especially problematic to both Jon and I given the business implications of needing to spend a couple hours with each client getting them set up. Altium acknowledged that this was indeed an issue, and since our initial consultations, they now have an in-depth set up and usage video available on YouTube.

The video is an animation, which actually is beneficial because they can illustrate what's actually going on in the chamber, which was something that was confusing during the initial consultations we had on Skype. But there are still some issues that no video can clearly answer, and that remains an ongoing concern.

In my case, I burned through a cartridge in a single session, and sometimes faster. Given that these cartridges are neither "replenish-able" nor recyclable, this is a big issue. The cartridges are also not cheap at a little more than $10 a pop. For me, going through a 15-day cycle of intermittent hypoxia, that's $150. But the biggest issue is that it wasn't entirely clear that this was happening. The cartridges have a active dye that changes color as they are depleted, but the system is not perfect. Ultimately, it took me about five sessions to realize what was happening and to confirm it. Knowing now the obvious feeling of re-breathing excess CO2, I would not run into this again, but I don't know how you'd know this in advance if you'd never used such a device.

In Jon's case, the "burn rate" was not quite as substantial, but still fairly rapid nonetheless. Jon generally got through two sessions with one cartridge, but as noted in the introduction, he lives mainly at altitude and all of the testing of this product was also done at altitude.

If it works for pre-acclimatization, that represents a reasonable investment, because this is just a huge obstacle for athletes who do not live at altitude who wish to race at altitude. But as a general stressor? I am not so sure.

Device Usage

In both cases, this was a device that required relatively constant vigilance. You get the hang of it, but it's still not easy to keep your SpO2 in the "sweet spot" of 80-85%. Further, because controlling the gas composition is important, Altium chooses to make the unit without a hose because that hose is simply more volume of air to "manage."

My wife used a similar intermittent hypoxic device about 10 years ago that came with a relatively long hose, so that you didn't need to actually hold onto the unit. In the case of the Altium, you are holding this thing. I was able, with some effort, to arrange it on my desk so that I could work on my computer, but it was not at all optimal.

Basically, you are committing an hour to using this device. It's possible to watch TV while using the Altium, but the issue here is when you use it. I used it once watching TV before bed, but the problem is that it definitely is a stressor. The Altium is a workout. And you'll have the same issues as if you decide to do a workout right before you go to bed. I woke up in the middle of the night starving - much like you find at altitude, which spikes your BMR (Basal Metabolic Rate). And that was the last time I used it before bed.

So this presents a conundrum. It's a device that you need to be mindful of when you use it, and yet it requires a vigilance and commitment to use. If someone else is driving, you can use it in the car, but I wouldn't say that regular 1hr car trips are optimal. If you're a train commuter, I suppose you could use it there, since triathletes are used to people giving them weird looks anyway - and you will get weird looks. For me, with a bunch of kids, I didn't exactly want to take an hour out of the middle of my day to suck on a tube, especially without a very clear benefit.

In this way, the biggest obstacle to use of the Altium is really ergonomics. You just can't do anything else while you are using it, which doesn't make it a particularly attractive alternative to actually swimming or biking or running.

Nevertheless, it's clear that the Altium does something. And that's intriguing to me. I just would like it to be easier to integrate into my life, which I suspect in at least some ways bears more resemblance - now - to the life of the typical age-group athlete than it did when I was a single pro with plenty of couch time to use up during the day...

Jon's Thoughts

Jon was especially reticent to add stress to his life, since he claims that dealing with me on articles like this is one is stressful enough. Plus, since he lives at "real" altitude, it's not clear that the device would particularly benefit him. But I was leery about trying to evaluate this product entirely on my own.

Together, Jon and I made plans to attempt to at least verify some aspects of Altium's own findings. We both had initial blood draws - though based Altium's own research, we didn't expect to see any changes. Ultimately, my own testing was derailed a bit because of illness (thank you, preschoolers), and I wouldn't ascribe any confidence the my own blood test results. But Jon did conduct pre/post testing, as in Altium's own testing, and his results mirrored their findings - no significant change on typical blood markers.

Given that we already expected - per Altium's own findings and the established research -  that the impact was unlikely to be related to blood chemistry, we tried to establish a protocol for evaluating the Altium more as a general stress.

The Altium protocol calls for 15 sessions. Our goal was to split this up into five sessions that stood alone as a stress - meaning more than an hour removed on either side from training, five sessions that occurred immediately before normal training, and five after.

This was maybe a bit ambitious, since, as we discovered, simply using the device is a challenge, and scheduling an hour to complete devote to using the Altium is easier said than done. Ultimately, we fell short of exactly executing our idealized test, but whether or not that was a significant factor in our experience is difficult to say. Certainly our own test added yet another variable to existing IHT research, something that's a risk given that we were already in a pretty tenuous position with N=2.


Ultimately, I'd like to see a robust, controlled trial on the use of the Altium for pre-acclimatization to altitude. I can see that being a huge advantage not just for triathletes wishing to race at altitude, but also hikers and skiers and other recreational athletes who often struggle with altitude sickness during recreational pursuits.

As far as a "training device," I'm intrigued by the Altium, but not for the reasons I expected. I find the topic of "metabolic training" to be very interesting. The growing research on fasted training and intermittent fasting are compelling. But they also give the same cause for concern as altitude training.

When you add another stress on top of the normal physiological stresses of basic aerobic training, you are taking a risk. You can spur greater adaptation. And you can also push your body too far. A fasted run that leads to illness is clearly a bad tradeoff, even though fasted has shown proven effective . And in that way, I'm much more comfortable with things where there is only a single primary variable - intensity. It's much easier to simply slow down than it is to increase blood sugar. And if, like many athletes, you have developed a reasonable sense of how much you need to eat to fuel your training, it can be hard to throw a wrench into that equation.

The older I get, the more wary I am of adding additional stresses to my training. The main reason to be a "full-time" pro is because you are not forced to look for ways to be creative. You swim, bike, and run as much as possible. However, I know that's a luxury that not everyone has. Both for the time-constrained and those who wish to compete at an elevation significantly different from their home environment, the Altium i10 represents an interesting device. There's still more research that I hope is done, but for the "biohackers" among us, you may want to consider giving IHT a try.

Jon agreed with the bulk of my assessment, but his own conclusions are as follows,

Did I "feel" any better? Hard to say. Did I ski, swim, bike, or run faster? Again, hard to say. Now, this is not to say that the device doesn’t work, it’s simply very difficult to accurately test for and measure an effect in vivo. In vitro, my findings support the results described above of no change in blood chemistries.

I agree with Jordan in that perhaps the most practical application is for use for sea level athletes preparing to race at altitude. Without a doubt the best strategy is to arrive to the venue two to three weeks early, but how many age-groupers have that luxury? Very few. Given this, the Altium system is most likely better than nothing. Clearly much more research needs to be done, as good scientific research takes time and altitude research, by its very nature, is a slippery beast. There is a wide range of response and adaptation over different athletes, so devices and protocols that can be very effective for some can be utterly useless for others. In other words, "Your mileage may vary."

In summary, this is something to watch. I believe it is too early to call it a hit or a miss. Jordan described the situation with altitude tents and altitude research very aptly in the opening section of this story and I echo all of these sentiments. If you have the resources, an open mind, live at sea level and have an altitude race on the calendar, I would consider trying it. I think it’s highly unlikely that its use would hurt in any way (other than possibly compromising recovery, so you’ve been warned) and it might make you feel just that much better when you get off the place in Machu Picchu. If you do try it and feel it was a waste of money, send your angry letters to Jordan, as this was all his idea.