Photography by Jered Gruber & Matt de Neef

Eight weeks of simulated altitude training – results and conclusions

by Stephen Lane

Melbourne-based A-grade cyclist and training adaptation PhD student Stephen Lane has spent eight weeks doing simulated altitude training sessions at the Bodyology facility in south-east Melbourne. He's been writing for CyclingTips about the experience and in this final part of a three-part series, Stephen runs through the results of the experiment and considers the effects the training has had.

Eight weeks is up and it seemed to fly by. It’s time to sum this whole experience up. Did it make me faster? What were my subjective findings during and after these 24 hypoxic (reduced-oxygen) sessions?

It has been a big learning curve. I will admit I still understand very little about this method of training but my interest has been sparked and I’m now dreaming up studies I can do to better understand the effects and benefits of altitude training.

First I’ll run through my pre- and post-program BODPOD testing. As a reminder, the BODPOD system can be used to determine your body composition, including the percentage of body fat and lean muscle you have.

There was really no major change in any of these numbers (see Table 1 below). We didn’t control for my diet or training so it is hard to say either way if the hypoxic sessions were the cause of the small changes.

Although I didn’t see any major changes under these conditions the BODPOD is a very simple and accurate way to track changes in body composition. For example, we all wouldn’t mind losing a little bit of fat mass. However, if not done correctly it can result in significant losses in fat free mass, primarily muscle.

This can result in a significant reduction in power output and performance can be negatively affected as a result. The BODPOD measures both and can track the changes in different body tissues making it a valuable tool to a dedicated athlete.

Table 1: Changes in body composition

As you can see from Figure 2 and Table 2 below, the post-altitude-training step test showed a good improvement on the pre-training step test. (As a reminder, the step test involved increasing the power output throughout the session to test blood-oxygen saturation levels at different power outputs).

As I mentioned in my first article the guys at Bodyology and I were very surprised at how low my oxygen saturation (SaO₂) dropped during first time in the chamber. It was alarmingly low and if it had remained that way I would probably have been doing supervised sessions to ensure my safety.

If you keep in mind that 80% SaO₂ is deemed the ‘safe’ lower limit, I started and ended below that! However, I quickly learnt that controlling my breathing elevated the values and as you can see in my post-altitude-training test numbers, my SaO₂ remained significantly higher throughout.

Did this make a difference to my performance both in and out of the chamber? Yes, I believe it did.

The step test showed that training in simulated altitude not only improved my oxygen tolerance but also marginally lowered my sub-maximal heart rates by about 5bpm at any given workload (see Figure 2 and Table 2 below). I can’t discount daily variation in heart rate but this is the direction and also the degree of change I would expect to see.

I think one of the other main points was that in my final stage at 300W in the pre-training test I was cooked and had nothing left in my legs. In the post-training test I was still OK and felt as if I could have continued. I think this ability to push harder with reduced oxygen availability is one major adaptation that occurs, as discussed in my second article through the observations during my interval sessions.

By the end of six weeks of intervals (I didn’t start intervals until two weeks in) I was holding nearly 40W more for each five-minute interval. I think this is proof enough that either metabolic or neural adaptations occurred.

Figure 2: The effect of simulated altitude training on power output and blood-oxygen saturation. The dashed blue (pre-training oxygen saturation) and green (post-training) lines show that Stephen was able to maintain a greater concentration of oxygen in his blood for a given power output. The solid red (pre-training heartrate) and purple (post-training heartrate) lines show that for a given power output, Stephen’s heartrate was lower as a result of the training at simulated altitude.

Table 2: Data for the above figure.

Onto the laboratory performance tests (see Table 3 below). I found no major change in values for VO₂max (maximum oxygen consumption) or power at VO₂max (PPO) nor did it feel any easier or harder during the test (it just hurt as usual!)

In saying that, I really didn’t expect to see any major change either. I’ve done more VO₂ tests than I can remember and my values have never really changed too much when I’m at a decent level of fitness.

Most studies investigating the effects of hypoxic training don’t report any major change in VO₂max or any markers of O₂-carrying capacity in the blood, especially in already-well-trained subjects.

That said, I believe it may increase values in individuals who aren’t at an elite level, as moderately-trained individuals appear to be more responsive to such a stimulus.

One of the most interesting results came from my time-to-fatigue effort at 150% of my power at VO₂max (150% PPO). For this test I set our fancy bike in the lab to a constant power, which is independent of cadence and how hard I push. The bike just holds the power and I gradually fatigue until I can’t turn the pedals anymore. Yeah, it hurts as much as it sounds!

In the pre-test I lasted 83 seconds; in the post-test I lasted 87 seconds. This doesn’t sound like much of an improvement but it is actually a 5% increase in time-to-fatigue. It still hurt the same but I think that a 5% improvement in anaerobic capacity is a good gain.

Some recent evidence suggests that hypoxic sprint training can improve the muscles’ ability to clear and buffer lactate. One study of note revealed good increases in repeated sprint performance after just eight training sessions over four weeks.

What is interesting about my improvement is that I really didn’t do any specific efforts that aimed to increase my anaerobic capacity. I spent the entire eight weeks of training both in and out of the chamber doing longer sustained aerobic efforts as I was in an aerobic build phase of my training.

I’m really only now starting to incorporate above-threshold sessions to begin to ramp up to some of my bigger goal races in a few weeks’ time. So the periodising of the altitude sessions within my overall training plan possibly came a little bit early. I really think a short block of simulated altitude training closer to a key event is more appropriate and would probably reveal more measurable performance gains.

Table 3: Changes in laboratory performance tests.

So it’s time to wrap up this experience and bring to light some of the changes I’ve seen in my fitness and performance over the past eight weeks. Firstly I’ll start with my changes in fitness.

My performance tests really didn’t show a great deal of change in my physical capacity. However, I really think this was mainly due to the fact that I already started with a decent level of fitness. The demands of and physiological responses to simulated altitude training have been shown to elicit good changes in performance but not necessarily measurable physiological variables like VO₂max.

I feel as if it has improved other variables like my muscles’ ability to buffer lactic acid, which in all reasoning should provide significant performance benefits. My time-to-fatigue test is indicative of that.

On the road training and racing I do believe the sessions have helped. I’ve had some pretty decent results in recent time trials and I believe the altitude sessions have contributed to that. One factor is my breathing.

The altitude sessions have forced me to consciously control my breathing. Now in races I find myself focusing on this and feeling significant reductions in perceived exertion when I begin to control it. Whether this is elevating my blood SaO₂ like I’ve reported in the altitude step test or whether it’s just a more efficient way of breathing I’m not certain but it definitely helps.

In the last two weeks I’ve begun to lift intensity within my training and incorporate some shorter anaerobic efforts. My power numbers have surprised me on several occasions. Even though I haven’t been doing any specific high-intensity training I am hitting numbers close to what I have previously achieved after a good block of anaerobic type efforts.

I believe there have been some metabolic adaptations within my muscles and possible neural changes that have occurred that I haven’t really tapped into yet.

All in all this experience has led me to believe that simulated altitude training does have a place in a periodised training program. I think the biggest benefit would be done as a block of training in the final weeks leading up to a goal race, particularly if the race is at altitude. I will definitely be planning another block of simulated altitude training leading up to my annual Tour of Bright campaign.

Hopefully this year I can go one step further up on the podium with a little extra help of some specific efforts in the chamber. I also think that in combination with the use of an altitude tent and some extra hours spent sleeping at altitude significant improvements in blood parameters resulting in an improved aerobic capacity would occur.

I think the changes in blood parameters and aerobic capacity noted in the research are due to the longer hours of exposure when training and living at altitude and a simulated altitude tent would make a good substitution for this.

I’ll finish up with a big thanks to Michael, Andy and Ben at Bodyology. The facilities there are first class and so is their expertise. If you are serious about improvements in performance and are familiar with the new ‘marginal gains’ theories going around at the moment you would understand that small things count and simulated altitude training is definitely an avenue that you should explore.

Lastly thanks to David at Altitude Training Solutions (ATS) for the loan of the home-based altitude unit. If you haven’t got the time to get into a chamber the portable units (which can be hired from Bodyology or ATS) are just as effective as the chamber but provide a far more convenient option for the time-poor athlete.

It’s been a terrific experience and I hope I’ve shed some light onto the performance and physiological gains possible with this newly emerging training aid.

You can read part 1 of Stephen’s three-part series here and part 2 here. Thanks to Stephen for taking the time to do the training and write about it for us. If you’d like to read more of Stephen’s work, check out his great blog Human Performance Technologies. Thanks to the crew at Bodyology for providing Stephen with the eight-week block of simulated altitude training sessions. If you’d like a free one-week altitude training trial, contact Ben Griffin at Bodyology before August 31, 2013 and mention this article.

Tags: Altitude Training, Stephen Lane

Greg Ski

Looking at those figures it sounds like a waste of time for most people. All but elite athletes would be much better off working on their aerobic capacity (regular long steady rides) rather than ‘training at altitude’.

My 2 cents.
http://davidjohnstone.net/ David

This is interesting, but not very conclusive.

They say the plural of anecdote is data :-)
- JBS
  
  I agree interesting, but its ultimately proved nothing.
  
  But the plural of anecdote is anecdotes! It most definitely is not data, and any student of my that suggested that too me would get a lesson in scientific reasoning quick smart.
  - http://davidjohnstone.net/ David
    
    It’s a shame those short little sayings never capture all the nuance that a longer and more complicated sentence can express.
    
    That is, I probably completely agree with you. The idea of that saying is that you should have a large sample size, and that a sample size of one normally isn’t very useful.
    - JBS
      
      Yeah, we’re on the same page.
      
      I just have an issue with that saying because the underlying inference is you can look at an apple and an orange and then tell how a lemon grows. Anecdotes are wonderful for developing an idea for testing, but completely useless for testing an idea.
mac

All I know is that every time I come back from cross-country skiing in Colorado (@~3000m+) my endurance and fitness levels are noticeably waaay improved. I realise that it is very personal the training effect of altitude, but for me it seems to work.
- Greg Ski
  
  It would be interesting to see if you did the same training at sea level whether the performance benefits were different and how. Cross-country skiing can be bloody hard at any altitude so I’d say you’d reap some benefits anyway.
  - mac
    
    I guess my point is that I am usually fairly well “trained” at that time of year (summer here with plenty of training/crits etc.) but I always come back from CO even fitter. I could train my arse off even harder on the bike at sea level and I don’t see the same performance gains.
Mark_Kelly

Umm there’s a typo in the first table. The row labelled “fat free mass” should be “fat mass”
Hardo

Ok, I’m going to put this one out there with absolutely no proof or evidence… just for the hell of it.

I live in a very hot and humid climate, where I recently trained for a 10 day riding event which was to be held in a cool, and much less humid climate.

During the ride, which certainly wasn’t a walk in the park, I felt really good. Much better than expected considering how I felt during training in the heat and humidity, which wasn’t that great.

Training in heat and humidity seems to rip every ounce of moisture from your body and you just feel totally depleted and fatigued. Whereas, when riding in a much cooler climate, physically I felt really comfortable and dare I say stronger. I was nowhere near as sweaty and I drank half of what I’m used to drinking. And I slept beautifully.

I couldn’t really say if I was actually physically stronger from training in humidity… but it certainly felt that way.
donncha

Given your summary, it would appear that altitude training improved your ability to ride at altitude, but did not improve your ability to ride at sea level beyond what would have occurred anyway had you done the same training without any altitude sessions.

Seems like a waste of time unless you’re planning to race at altitude.
- muz
  
  Don’t knock it until you’ve tried it donncha. I have a home unit jobby and I def go better after I’ve done a block (and I definitely go worse when I’m in that block)
  - donncha
    
    I can do an 8-week block of structured training on my own, for free, and see improvements. If I was considering paying for altitude sessions and/or home units, I’d just like to be sure there was a decent return on that investment.
    
    I guess, at this stage, I’m just struggling to see evidence of a decent gain (at sea level) that can only be attributed to the altitude aspect rather than just having done X amount of training.
Touiti

The results don’t change much for this well-trained athlete, which suggest that the effects could be even lower for elite professionals athletes.
Altitude training is a bit overrated, because the benefits could come from the hard rides in the mountains (where maintaining a higher power output is easier than on the flats) not from the heights.
In my opininon, altitude training is mainly used to distort the biological passeport. Because changes in hematocrit values can be “explained” by altitude training while doping. And it is hard to prove doping in these conditions because it can be argued that everybody have a different response to altitude, which is true.
But in comparison, it is well known today that hematocrit values over 50% is a serious proof of doping.
john

Being both a cyclist and cross country skier. I found the articles rather useless at best. First of all, altitude parameters are multiple. When doing an altitude race, are sleeping at altitude, is the race starting and ending at altitude, is this an Himalaya stage race ? Second, are you climbing at altitude or just grinding some humps or doing a crit in downtown Boulder… I am gonna stick to the following rules:
If you are going to climb your ass off, do yourself a favor and sacrifice what you eat, starve yourself to death and become a chicken legged wonder with power. If Froome and Wiggins hasn’t proved that. That body mass going to save you years of altitude anything.
Second all forfathers of altitude training in xc skiing have been adamant: some skiers can fly into a world cup from sea level and do very well on day one, others will feel terrible. There are some athletes out there who simply push better trainings at sea level to become better athletes at altitude.
Finally, altitude training is not how hard you go at altitude, in fact that could very much step you back a shitload. Ask any norwegian, canadian athletes, train hard low and sleep high and if you are going to maintain altitude fitness, you better back up and level 1 and 2 at altitude or you are gonna burn.
These are all reasons why I find all this measuring a complete waiste of time, much like stacking pancakes of supplements. Keep thing simple, rest right, eat good, learn to recoup and appreciate extreme power froma high volume base. The rest is expensive guru bullshit.
echidna_sg

glad to see this article - I was beginning to wonder when we would see it ;-)

I for one am glad that someone has taken the time and effort to assess training when under an external stressing environment beyond the norm. We see recent claims of Froome being born and living at high altitude as a child/teen and racing MTB in this environment as being responsible for his motor - is there any evidence that non-endemic people can get this kind of benefit without generations of minute change?

Living in a hot and humid environment myself, I see the benefits of my regular training whenever I go home to Melb where the cool air and dry environment just make riding and running so much easier than it is in my normal training environment. Training in an environment that taxes your body more than “normal” definitely makes training or racing in a less stressful environment far easier for me!
Trainedinfrance

Simulated Altitude Training (SAT) is a fantastic tool to have in your training box. But it has to be matched with the understanding of the breathing mechanism and how the breath works under load and in a reduced-oxygen environment.
Throughout the series of articles written by Stephen he has clearly stated numerous times that he through his SAT experience he has become aware of, and manually started using his breath. And it is in the management of the breath that SAT is powerful.
An athlete who undertakes a SAT program would be wise to monitor their training efforts with monitored breath length and breath counts per minute to assess their adaptation.
There are no real benefits (other than marginal) gained from SAT if you are still hyperventilating during your intense efforts and races.
How is this noted in the real world? -A good indication of a successful SAT program is the ‘running out of muscle before running out of breath’ perception.
Ben

good to see some discussion on altitude training. Like all different modalities of training there is never going to be total agreement in what everyone thinks is the best method of training. Whilst there is starting to be more and more research in altitude training (most of it very positive) you need to look at what the best coaches and athletes of endurance athlete’s around the world are doing. I have been lucky enough to learn and work with some of the very best, which helped shape my belief in the benefits of altitude training. Remember if you are waiting for research to ‘prove’ something then you are going to well and truly miss the boat and the worlds best athletes and coaches are about 10-15years ahead of the research. I would argue that most athletes (amateur or elite) would get a very good response from a well planned altitude program. I welcome any reader to come in and try a week on us for free and therefore be able to make a slightly more informed decision for yourself. Appreciate that everyone will always have their own views though.
Ben Pilot

So back to what I said at the beginning…. WOFTAM…..

I’d like the see the same test done over 8 weeks now SLEEPING at say 2700m for at least 8 hrs a day….

I think there would be a far bigger gain ;) for me, the gains just seem standard with training.
Ciclismo-Espresso.com

Wasnt there a saying “train low, sleep high”?
It would be interesting to see a test with a tent used while sleeping, and then train normally at sea level.