This article provides a brief overview of altitude training and is primarily aimed at the lay person or exercise professionals new to this form of training.
With numerous evidence-based fitness benefits, altitude training is becoming more readily available in commercial settings. This brief article takes a closer look at what altitude training involves and who it may be suitable for.
2.0 Background to Altitude Training
Altitude training in an oxygen-depleted (hypoxic) environment has been used as a training aid by professional athletes since the 1968 Mexico Olympics, when the link was made between altitude and improved performances in certain events.
Since then, altitude training has been adopted by sports institutes and clubs, but it has only reached the mainstream in the past decade, through altitude training centres and gyms with altitude training chambers.
Previously, altitude training was conducted by athletes at natural altitudes (i.e. travelling to training areas in countries situated at a high altitude above sea level or at sea level) in preparation for a competition.
This was not always easy to do, so simulated altitude became more popular. In simulated altitude the amount of nitrogen in the atmosphere is increased which lowers the oxygen content, thereby simulating what it is like to be at altitude.
Further, unlike some fitness trends, altitude training has a growing body of scientific research behind it, making it an interesting consideration or proposition for those exercise professionals who want to add it as a new element in their client programmes.
3.0 How Does Altitude Training Work?
Altitude training conducted in a simulated setting is known as intermittent hypoxic training. It is also known as the ‘Live Low, Train High’ approach, where an individual lives at sea level but trains in a hypoxic environment.
At sea level and real altitude environments, the oxygen content in the air we breathe is approximately 20.9%. However, with real altitude environments, the reduced air pressure reduces the amount of oxygen molecules available for the body.
In a simulated altitude environment, the air pressure is the same as at sea level, but the amount of oxygen molecules is reduced down to around 13.5%.
From a physiological perspective, the body is getting an increase in haemoglobin mass, which is a direct measure of an increase in red blood cells. If a person has got more red blood cells, they have more oxygen being transported by their body and can thus get performance gains in a range of areas.
Hypoxic environments also trigger a cascade of changes at a genetic level. There is a particular gene, the hypoxia-induceable factor 1 alpha, which rapidly senses a hypoxic environment, and that has downstream effects on approximately 20 or more other genes, which can switch on other proteins in various pathways.
4.0 What are the Fitness Adaptations?
Studies suggests that altitude training can improve a range of fitness measures, across a variety of activities, with benefits taking effects within weeks. Improved fitness measures include:
- One repetition maximum (1RM);
- Repeated sprint capacity;
- Prolonged endurance such as time trial performance.
Studies of elite athletes reveal a small but significant improvement in haemoglobin mass of up to 5%. Other research demonstrates:
- An increase in muscle buffering capacity; or
- The ability of muscles to tolerate lactic acid build-up during exercise.
A 2013 Swiss study revealed that eight repeated sprint cycling sessions in hypoxia done over four weeks increased the number of sprints prior to exhaustion by 38% and enhanced muscle blood flow. Another study published in the Journal of Applied Physiology found that six weeks of twice-weekly high-intensity running in simulated altitude boosted VO2 max and increased run time until exhaustion by 35%.
Benefits may be seen within three weeks and endure for approximately four weeks, according to the results of some studies. However, as with other forms of training, consistency is key. Simulated altitude training must be incorporated into a training programme two or three times a week because, without regular exposure, the physiological effects revert to baseline.
5.0 Who Can Benefit from Altitude Training?
Altitude training is suitable for a variety of groups, including:
- Professional athletes.
- Semi-professional athletes.
- Pre-acclimatisation market: e.g. people who are trekking to places such as Everest base camp.
- Amateur athletes: e.g. obstacle course racers (OCR).
- General population: e.g. those after general health and fitness.
6.0 Training Facilities
There are several training facilities that can simulate levels up to 5000 metres but, generally, 3500 metres is the normal simulated training altitude.
Services that may be on offer include:
- Own training: Clients my want to just rent the space and conduct their own training.
- Class: Facilities can offer generic and tailored training to clients.
- Virtual programmes: Facilities can offer virtual training to aid immersion.
- Personal training: One-to-one and small group training for clients.
7.0 Incorporating Altitude Training into a Training Programme
Although altitude training is suitable for most people, it should be viewed as an add-on to an already well-structured and progressive training programme.
It is recommended for those whose training is already at a good level, so they can maximise their gains.
Altitude training can also be utilised as a stimulus if a client is plateauing and, it is worth mentioning that, because altitude training increases the load or stress which an individual is under, it may impact their training capacity. In practical terms, this means the individual will have to work harder to complete the same amount of work, with a higher heart rate, lactate and perceived exertion. Consequently, they may reach a point where, for example, they might not be able to run at 10 km per hour and have to drop back to 8 km an hour. Important to consider regarding client psychology and motivation. Alternatively, the individual could lower the intensity and get the same if not greater gains.
For those returning from an injury, altitude training can help them maintain cardiovascular fitness while they are rehabilitating. For example, an individual with a lower limb soft tissue injury might not be capable of running or find it uncomfortable. In this scenario it is possible to conduct bike sessions under hypoxic conditions to train the aerobic system with less mechanical load on the body.
8.0 Training Safety Factors and Considerations
There are a number of practical things to keep in mind when conducting altitude training, including:
- Ensure blood saturation is monitored:
- Small devices that are attached to a finger, known as pulse oximeters, are used to monitor blood saturation levels.
- Blood saturation is usually around 97 or 98%, and when you go into altitude that decreases, but if it drops below 80% it is recommended that individuals either leave the room or decrease their workload.
- Altitude training facilities should have these readily available, and educate clients on how to use them.
- Get medical clearance where necessary:
- As with fitness training in general, clients with heart conditions or pre-existing medical conditions should obtain medical guidance before commencing altitude training.
- The heart has to work a little harder in these conditions, so constant monitoring is key.
- Clients with low iron levels should also consult their medical professional first.
- Avoid hypoxia if a client is unwell:
- A person needs to be in a physiological state where they are ready to adapt to a stressful stimulus, meaning if they are run down or sick they should not conduct altitude training.