Altitude Training

Altitude training (or hypoxic training) is the practice or training for several weeks at high altitude. Preferably it’s done 3000 metres above sea level but due to availability of a suitable location often occurs at a lower point. Normal breathing above 5000 metres is impossible for continued existence and therefore training is also below this point.At these higher altitudes the oxygen levels remain the same (around 21%) however the barometric pressure (air pressure) is reduced and therefore the partial pressure (the pressure that each gas alone would have if occupying the same volume of space) also decreases.

Altitude training is only a recent development in sports training that came to the front after the 1968 Olympics (held at Mexico City, which is 2290 metres above sea level). No world records were broken in events lasting longer than 2.5 minutes which stimulated further research into this type of training and its impact on performance. Despite a lot of research into the area the true effects are still not well established. Many athletes are now taking different science based approaches such as using altitude simulation tents, altitude simulation rooms or mask based hypoxicator systems (where the barometric pressure remains the same but the oxygen level is reduced, still reducing the partial pressure of oxygen).

Training at high altitude is a must to acclimatise before competition at altitude, however the benefits of high altitude training for sea level competition are still in controversy and brought about the method of ‘Live High – Train Low’. This method involves living for at least 12 hours a day in high altitude (mostly while sleeping) for three weeks but doing training at lower altitude levels. Determining the optimal doses of altitude training is also required to meet your specific needs. Factors include:

· The length of daily exposure

· The number of consecutive days exposed

· ‘Stair stepped’ altitude acclimatisation (progressive)

· Maximum altitude

Whilst at altitude training, only the aerobic system is affected (as it’s the only energy system that requires oxygen) and has many physiological changes (that can be beneficial and also negative).The many impacts that high altitude has on preparation and performance include the following:

Immediate responses to altitude

Positive affects include:

· Ventilation rate increases – Breathing faster and deeper to get more air in, so more oxygen can be obtained due to the lower partial presence of oxygen. This may cause hypoxia (deficiency of oxygen).

· Heart rate increases – Helps to offset the lower partial presence of oxygen so normal functioning still occurs.

· Increased cardiac output – The increased heart rate means the cardiac output also increase.(20% increase at rest and sub maximal exercise but no change in maximal heart rate).

· Increased haemoglobin levels – The oxygen carrying cells are more prevalent to carry more oxygen around.

Negative affects include:

o Appetite decreases – Can potentially lead to lower iron levels (needed for haemoglobin production) and also lead to loss of muscle mass.

o High fluid loss – The dry, cool air can mean you lose large amounts of fluid.

Longer term adjustments

Positive affects include:

· Increased natural hormone erythropoietin (EPO) production – This increases red blood cell mass (which delivers oxygen to working muscles).

· Increase in VO2 maximum – The maximum amount of oxygen the body can use/convert to work, giving you more oxygen and longer working time. This is also due to the increased level of mitochondria (the cells that help turn oxygen into energy).

· Capillary volume elevated – More pathways for blood to muscles (improved muscle oxygenation).

· Decreased maximal heart rate and cardiac output – Due to acclimatisation of lower oxygen levels.

· Increase lung ability to exchange gases – The lungs can take more oxygen into the bloodstream.

· Change in Ph (acidity) – This is due to internal organs adjustments causing biochemical changes.

Negative affects include:

o Thicker blood – The increased red blood cells creates thicker blood which means the heart has to work harder to pump the blood around the body.

o Loss of body mass – Due to loss of muscle tone and increased metabolic rate.

o Psychological affects – Often being isolated, away from family and long distance travelling each day can affect a person’s mentality.

Time spent at altitude

The time spent at altitude training has many variables affecting it, which can include:

· The height at which you are training

· The time spent each day at altitude (training method)

· The aim/purpose you want to get out of it

· Different individual responses/acclimatisation

The height at which you are training:

· The length of time spent at altitude will depend on how high your ‘camp base’ is located. The higher up in the atmosphere you travel the less dense the air gets and availability of oxygen.

o At 2500 metres you will need to stay longer than 3500 metres.

The time spent each day at altitude:

· The training method (live high – train low, live high – train high or live low – train high) will affect the duration you will need to stay to acclimatise.

o Staying at altitude (high – high) doesn’t necessarily benefit you the most. It leads to ‘detraining’ which has negative gains which is the reverse effect desired by the athletes.

The aim/purpose you want to get out of it:

· This can vary upon individuals and thus amongst time spent. Sprinters may use altitude training for different purposes to long distance athletes. Some athletes may want different benefits out of altitude training which can vary in length of acclimatisation.

Different individual responses/acclimatisation:

· Certain individuals may take longer to acclimatise and gain the benefits of altitude training and therefore need to stay longer.

o Some athletes may also use progressive overload techniques to gradually acclimatise to a lower altitude before moving to a higher location. This is a lengthier option but can rule out side effects of sudden altitude increase (such as altitude sickness).

Acclimatisation is the gradual adaptation to hypoxic conditions. It involves three phases that occur over a two to three week period for maximal results. These phases are:

· Phase 1 – Increase in lung ventilation.

· Phase 2 – Erythropoietin production (causes increase red blood cells, subsequently increasing haemoglobin levels).

· Phase 3 – Increased capillarisation of muscle cells in the blood.

These individual variations will have an influence on how long you spend at altitude. The ‘Live High – Train Low’ method harnesses the benefits of altitude whilst some of the negative affects are avoided and is most commonly used. This technique requires the athlete to stay for around 20 days (3 weeks) with at least half a day (12 hours) spent at altitude, for altitude acclimatisation. A recent study in Finland showed no difference in spending 12 hours or 24 hours a day at altitude. 6 – 8 hours still showed some physiological gains but not as many as 12 hours.

Maintenance of benefits of altitude training

Altitude effects will persist to continue at sea level for around 2 – 4 weeks after. Studies of the benefits of altitude training have shown varying results in accordance to beneficial maintenance. The main problem is there can be no control group at sea level to make comparisons with (time off training is different to time in altitude). “One of the major problems with these studies was the lack of a control group, where an equivalent group underwent the same training program at sea-level. Without a control group, it is difficult to separate an improvement in fitness and performance caused by training from the possible potentiating effects of altitude and maintenance.” (Excerpt from ‘Effects of equivalent sea-level and altitude training on VO2 max and running performance’ Journal of Applied Physiology).

Continually maintaining altitude adaptations can lead to benefits until this form of training ceases (going up for one week every month will maintain the benefits)!

Who uses altitude training and who benefits from it?

Anyone can use and benefit from the altitude training technique and/or simulations.

Main people who use altitude as a training method include:

· Cyclists

· Endurance runners (marathon runners)

· Elite athletes which predominately use the aerobic energy system eg. Tri athletes, swimmers, footballers.

· Mountaineers/hikers

· Skiers/Snowboarders

· Athletes who are preparing to compete at high altitude levels

Elite athletes and the general population both benefit from it, however elite athletes benefit by improved performance while the general population improve in health levels and overall wellbeing.

Some famous athletes who regularly use or used altitude training to enhance their performance to get the edge over others athletes include:

· Paula Radcliffe (British marathon runner)

o Female world record marathon runner

· Lance Armstrong (Retired professional road racing cyclist)

o 7 times winner of Le Tour de France

In conclusion, there are many physiological changes that occur whilst at altitude due to acclimatisation. These changes can be beneficial, harmful and vary from person to person. They’re not permanent, unless altitude training is continually maintained. Altitude affects performance and is vital for training when competing at high altitudes.

This concept of training is relatively new and research is still being collected and examined. Much of the research already conducted has varying results with some contradictions amongst them. Tests are also being conducted by the world anti drug doping agency (WADA) to examine if this form of training is illegal and a form of blood doping. A statement made by WADA is “If you live in the mountains, it happens naturally. If you live at sea level, it doesn’t. I mean, it’s pretty easy…”

The future of altitude training is in jeopardy but in the mean time, many athletes use it to improve performance!