Athletes have long used high-altitude training camps as a means to push their bodies and improve endurance and performance. At the same time, scientific professionals debate the effectiveness of altitude training on athletes. One thing Altitude Dream has learned over the past 15 years is that everyone responds differently to training at altitude or simulated altitude.
In the news
A recently published review in the journal Sports Medicine highlights how athletes can use an elevation or hypoxic stimulus to improve their long-term or short-term performance. The leading researchers in this article help interpret and present existing literature on altitude training in a way that is approachable and understandable for the average athlete, coach or fitness enthusiast.
Alex Hutchinson of Outside Magazine, who specialises in writing about fitness and sports science, recently published an article highlighting the key points of altitude training. Hutchinson's article is an excellent summary of the researchers' recommendations. In light of this article, we wanted to share more about two of the issues Hutchinson raises, as these are topics we encounter on a weekly basis in interactions with athletes and are often misunderstood.
What we know about blood
Every day our customers ask: "To what extent is my haematocrit and haemoglobin affected by your systems?".
This is a very understandable question as the subject of altitude training - real or simulated - has been the subject of disproportionate attention to haematological adaptations including, but not limited to: increases in haemoglobin [1-11], increases in haemaocrit [4,5, 7 , 8], increases in red blood cells (mass and volume) [4, 12], and increases in reticulocytes % [4, 5, 7].
While this is an important physiological result of altitude training - it helps improve the body's oxygen transport capacity - it misses the bigger picture of how other body systems are affected by and respond to altitude training to produce similar performance-enhancing adaptations.
Although it is often important for our clients to realise an increase in haematological markers, this usually takes at least 3 weeks. Meanwhile, and in a much shorter time frame, athletes can also expect other physiological adaptations that can result in performance improvements independent of haematological changes. These adaptations are much less discussed compared to changes in red blood cells, but are arguably just as important for training performance, both at altitude and at sea level.
Example
For example, high altitude training increases the oxidative capacity of muscles [13, 14] by "increasing gene expression related to mitochondria, the aerobic power plants in your muscle cells, which may make your muscles more efficient", says Hutchinson . In addition, muscle fibres have been shown to increase in size and are associated with increased capillarisation [13]. Muscles have also shown the ability to improve buffering capacity through various changes in gene expression [15], meaning they can become better equipped to handle changes in acid-base balance associated with intense exercise. These adaptations may of course be the key to improved performance and accelerated recovery.
Why it matters
The key point is that while haematological adaptations are an important product of altitude training, they are only one piece of the puzzle with respect to the physiological adaptations that promote performance enhancements. While these changes are what most athletes associate with altitude training, they are really only the tip of the iceberg and we are glad that Hutchinson and Outside have finally brought that message into the mainstream.
Non-responders?
Altitude has been understood and used as a performance-enhancing stimulus since the 1960s. Despite this fact, it has also long been suggested that a certain subgroup of the population may not benefit [at all] from altitude training, regardless of the season of implementation or the duration of the training programme. These athletes have also been classified by some as "non-responders".
Interestingly, however, in our 15 years of experience with athletes, including a range of talents, we have noticed that with enough time and an appropriate acclimatisation strategy, even athletes who have difficulty adapting will eventually do so. We also noticed that people with previous altitude experience responded better and faster to our systems, while those with little or no experience seemed to take longer. This principle applied regardless of whether the user was a professional or recreational athlete.
Although it is possible that the studies showing non-responders are one-offs, one cannot ignore the well-established individual variation that exists between many of the physiological responses to hypoxia [16-18]. As such, and as with all advanced training programmes, altitude training requires good planning, strategic implementation and careful monitoring to be successful [19]. More importantly, it must be individualised. Thus, it is more likely that studies revealing "non-responders" have actually only shown that generic altitude training does not produce the same results for everyone. However, with more individualised tactics, the so-called "non-responder" may start to show changes in performance!
More research on this subject is undoubtedly needed [20], but our suspicion remains that the so-called 'non-responders' are more likely to be individuals who may have a greater sensitivity to altitude and who may also benefit from a more strategic and individualised altitude programme compared to the average athlete.
It also seems that there is a cumulative benefit to altitude training, which means that you should notice compound benefits as you do more altitude training. So get started today and be consistent!
