How Living in the Mountains Can Improve Exercise Performance
How does high altitude living/training benefit endurance performance?
For decades, high altitude living/training has gained popularity to improve performance for endurance athletes. Marathon runners, cyclists, triathletes, and swimmers, have long used this strategy as a way to improve performance at sea level or to adapt to performing in competitions at higher elevations (e.g athletes who were used to training in high elevations dominated the 1968 Mexico City games — around 2400m elevation). Unlike other exercise aids such as blood doping, high altitude training is an ethical way to enhance your body’s ability to transport oxygen to your tissues to improve endurance performance.
Before going into whether this style of training is suitable for your goals, it’s important to understand how it works as a performance aid.
What is altitude/low oxygen training?
Initially, low oxygen training involved living and training at higher altitudes for several weeks at a time. Overtime, it has expanded to include living at a higher altitude but training at lower altitudes, to ensure that training intensity can be maintained (it’s super hard to train when you’re in a low oxygen environment!). Spending the majority of your day in this low oxygen (hypoxic) environment is enough time to induce changes in our body to improve endurance performance. To increase practicality even further, technology has now allowed for these low oxygen environments to be artificially simulated in a room. Athletes can now train and/or live in chambers that are simulated to mimic the hypoxic environment of high altitudes!
How does hypoxic (low oxygen) living/training improve athletic performance?
The most noted benefit of hypoxic exposure is the changes it makes in our blood, by increasing red blood cell volume and hemoglobin mass. These alterations towards our blood helps improve the ability of oxygen to be delivered to tissues, which can improve performance in endurance athletes.
How does hypoxia induce these changes to improve performance?
Hypoxic conditions induces these benefits primarily through activating the protein known as hypoxia inducible factor 1 (HIF-1). HIF-1 promotes the expression of genes involved in forming blood vessels and stimulating red blood cell production. It’s especially important to note the role of HIF-1 in stimulating erythropoietin (EPO) production, since EPO is responsible for stimulating the production of red blood cells. Increased levels of red blood cells in our blood becomes noticeable within 4–5 days after EPO stimulation.
Now that we know all about its benefits, what types of hypoxic training regimens are out there?
1. Live high, train high:
This training style requires individuals to live and train in a moderately high altitude (2000–2500m) for 3–4 weeks. However, training at such high altitudes impairs training intensity and could cause detraining.
2. Live high, train low:
This training style involves athletes living in a moderately high altitude (around 2500m) for around 18–24 hours a day, then training at a lower altitude (around 1250m). This allows for training intensity to be maintained.
Does the research out there show that living in a high altitude is effective in improving performance?
It appears that both live high/train high and live high/train low are effective in improving endurance performance. A study that recruited competitive runners had them complete 4 weeks of training at sea level.
Afterwards they either:
- trained and lived at sea level
- trained and lived at a moderate altitude
- trained at a low altitude and lived at a moderate altitude
Both altitude-living groups saw a higher VO2 max (max oxygen intake) and red blood cell volume, both factors that enhance oxygen-carrying ability to our tissues during exercise.
Another study was performed on 36 elite field hockey players to see the effect of living in high altitudes immediately (after 3 days) and after prolonged (after 3 weeks) periods. Living in high altitudes was shown to improve aerobic/endurance performance in both periods, showing that these benefits are long-lasting. Overall, there is a large amount of supporting evidence for how living in higher altitudes can improve aerobic/endurance performance.
3. Intermittent hypoxic interval training:
In this training style, you’re rotating between being in hypoxic and normoxic (normal oxygen) conditions while exercising. The hypoxic conditions would typically be in an artificially simulated high altitude room.
4. Live low, train high:
This involves living in normoxic conditions but training in hypoxic conditions. The training could occur in an artificially simulated room or in real altitude conditions, and allows for individuals to not have to spend as much time in a low oxygen environment.
Does the research out there show that simply exercising in hypoxic conditions is effective in improving performance?
When looking at the regimens that involves hypoxia exposure only during training, the results are more mixed. A study was done involving trained cyclists and triathlon athletes, where on 15 days out of 3 weeks they performed intermittent hypoxic interval training. This involved 3–5 minutes of training in hypoxic conditions, followed by 3–5 min in normoxic conditions. After 3 days, an increase in aerobic performance was seen, but this wasn’t sustained after 3 weeks.
Another study on intermittent hypoxic training involved 15 endurance runners doing 6 weeks of training at 80–85% of their max speed in a simulated hypoxic condition (5000–5500m), while living in normal conditions. The hypoxic simulation was effective in improving endurance capacity by 35%, but didn’t show any effect towards increasing red blood cell production.
Therefore, it appears that only being exposed to hypoxic conditions while exercising isn’t likely enough time to induce those benefits towards your blood’s oxygen-carrying capacity. However, it is enough time to induce other factors that improve performance such as: increasing mitochondria and capillary (blood vessel) density, myoglobin (muscle cells that carry oxygen) content, and VO2 max.
What are the optimal hypoxic conditions to promote performance?
It seems that 4 weeks at a minimum of 12 hours per day in hypoxic conditions is enough; but the longer the exposure, the greater the increase in red blood cell volume and hemoglobin mass. Any shorter duration can promote other benefits towards performance, but won’t have a substantial effect on improving the blood’s ability to transport oxygen. Upon returning to lower altitudes, these benefits to your blood remains for around 2 weeks. Therefore, the timing of living/training in these hypoxic conditions is an important factor to consider before an athletic competition.
Can we apply this information to improve our own performance when exercising?
If you are an elite athlete performing an aerobic/endurance based sport, low oxygen training/living (either artificially simulated or in real altitudes) is definitely worth trying out. However, it isn’t practical for most individuals to train or live in low oxygen environments. There are elevation masks that can be worn while exercising to mimic these lower oxygen conditions, but there isn’t a lot of research out there showing its effectiveness.
Overall, low oxygen living/training is very interesting to learn about and has a lot of evidence in improving endurance performance (if you’re able to spend 12+ hours a day in these conditions!). But it isn’t a realistic tool for those of us who live in lower elevations to incorporate into our lives.