Altitude training

As altitude training is referred to in the training theory in the broadest sense an attempt to achieve a training effect by natural or simulated altitude. Since the acclimatization to the lack of oxygen (hypoxia) due to the decreasing air pressure at high altitude, the most important factor in this form of training is, one often speaks of hypoxia. A special form of altitude training is the height adjustment training, which has a capacity increase at high altitude to the target. While the effectiveness of the height adjustment training is particularly well documented for endurance sports, the meaningfulness of altitude training is regarded as quite prepare for performances in the lowlands as controversial.

History

In alpinism, particularly in high-altitude mountaineering and in the aviation medicine is mainly focused on performance at very high altitudes. The Summer Olympic Games in 1968 in Mexico City were held at an altitude of 2240 m. The preparation for these competitions gave impetus to a first systematic development of methods of acclimatization training in preparation for performances at mid-height. The great successes of long-distance runners from Kenya and the highlands of Ethiopia also resulted in deep altitudes to a focus on high-altitude training in preparation for competition in the lowlands. Today, many specially equipped high-altitude training centers (usually at altitudes of approximately 2000 m ) is used. To simulate altitude specific training effects in deep layers procedure such as altitude chambers and training with breathing masks have been developed.

Effects of altitude on athletic performance

The conditions at high altitudes differ by several effective factors of which at low altitudes.

• Oxygen partial pressure: The barometric height formula describes the decrease in air pressure with increasing height above sea level. For example, the air pressure at sea level is 1013 hPa and at 2500 meters altitude only 740 Pa. The composition of air and hence the oxygen content is substantially the same at different heights ( in the relevant height of the training area ), therefore, the oxygen partial pressure decreases with increasing altitude linearly to the air pressure, so that a cubic meter of breathing air in the amount less oxygen than at sea level. The resulting lack of oxygen can result in a high altitude to altitude sickness and, in extreme cases, death.
• Air resistance / air density: The reduced in height air density leads to a lowered resistance to flow, which is especially relevant for sports such as throwing sports, sprint, cycling or skiing, since high velocities occur.
• Water vapor pressure of the air: Since the height of the water vapor pressure greatly decreases the breathing air must be more moisturized, which is particularly relevant at low ambient temperature. This leads to drying out mucous membranes and increased fluid intake. Lack of water can lead to thickening of the blood, which brings several disadvantages such as greater stress on the heart, impaired tissue oxygenation, tendency to thrombus and frostbite by poorer perfusion of peripheral regions of the body with it.
• Temperature: Most increases at high altitude on the temperature, the daily fluctuations in temperature rise, however.
• Radiation: Angle radiation, including in the ultraviolet region burdened body.
• Purity of the air: It is often found in high altitude lower air pollution.
• Psychological factors: The psychological factors such as the forces acting on all the senses different stimuli through landscape, social environment or changes in circumstances in height are still little known. However, there are indications that such circumstances may be relevant. Also, exposure to travel, for example, distance from home and jet lag are observed.

As a result of these influences major sporting parameters such as endurance, speed (especially speed of response ), motor balance and motor coordination are impaired even at a short height stay, but are very different reaction thresholds. Maximum strength and endurance, however, are hardly changed from acute hypoxia, effects become apparent only after prolonged lack of oxygen.

In various sports, these are differences of varying importance. While sports where shorter, anaerobic loads and high speeds occur, the amount an overall positive effect on the achievement levels, while increasing load duration withdraw positive effects such as reduced air resistance behind the negative effects of lack of oxygen. So almost all running competitions were won under two minutes with a new world record for example, in the 1968 Olympic Games in Mexico City, with all long journeys you, however, remained behind the current world records. The range was between an improvement of 1 % (100 -meter run ) and a deterioration of more than 6% ( marathon ).

Effects of residence and training in the amount

At not too great a height adjustment of the body to the altitude -induced hypoxia primarily by increased red blood cell production ( erythropoiesis ) takes place. The capacity of the oxygen uptake and transport is thereby increased, the effect is comparable to the blood drug. This effect, however ( one to several weeks ) to take a long time, until then prevails especially in medium and high altitudes to increase the hematocrit by decreasing the water content and hence the volume of blood plasma ( thickening of the blood ).

In addition, there is hyperventilation, circulatory activation (increased heart rate). The ability of hemoglobin to bind oxygen is reduced, so that it can be delivered easily to the tissue. Even at cell level, there is adjustments in aerobic and anaerobic metabolism of muscle cells. Hyperventilation has changes in acid -base balance result. Also neurophysiological adaptations such as increased reflex activity to occur.

These positive effects are offset by effects of altitude, which can not be compensated by acclimatization, such as an increased minute ventilation, a reduction of the maximum cardiac output and reduction of the buffering capacity of the blood. Such negative effects may lead to reduced training intensity and reduce the training effect of the altitude stay or completely negate. Some authors therefore available to the altitude training compared to general critical.

Technical possibilities for hypoxia

The previous effects of longer stays height relate to the stay in the natural height with its manifold implications. In order to achieve the desired effects of the major high-altitude training in an easily controllable frame, many attempts today to replace the natural height by artificially produced hypoxia. One way to do this is training or stay in vacuum cabins ( " Barokammern "). The advantages lie in the infinitely fast simulation of different heights and independence of weather, about the disadvantages are often small space (especially for longer stays also associated with psychological stress ). The same applies for height chambers that operate at constant pressure a change in air composition (reduction of the oxygen content ). Alternatively, masks can be offered, in which the exhaled air is inhaled again, and thereby decreases the amount of oxygen. A disadvantage of this is the rising level of carbon dioxide in exhaled air, which must be reduced by reabsorption consuming again. Moreover, the athletes is limited by wearing the mask in his freedom of movement and increased breathing resistance.

Implementation

Forms of altitude training

Especially when training in natural height is worked mostly on the concept Live High -Train High ( LHTH ). This means that the athlete lives a certain time at high altitude and also trains there. Due to the ease of accessibility of altitude training centers and the availability of altitude chambers alternative methods have been developed in recent years, however, because as a quick change between different altitudes is possible. In particular, the concept of Live High -Train Low ( LHTL ) is now regarded as promising: athletes who live in the highest, and sleep, but work on normal height, link the benefits of altitude acclimatization with the opportunity to train at full intensity, resulting in at training the height is not possible. Another option is Living Low- Training High ( llth ), where the athletes live in the lowlands, but for training visits the height. Training concepts, in which alternating phases of training in hypoxia and under normal conditions, are referred to as " Intermittent high altitude training " or " Hypoxiegestütztes training " and to combine the advantages of training in altitude and low altitude.

Which of these methods is best suited as a training method can strongly depend on the sport in question, but also on the particular athlete, as differences in individual fitness are suspected for altitude training.

Selection of the height level

As more than 4,000 meters above sea level is only one more inadequate acclimatization and some room for the loads that occur during training is necessary for a meaningful high-altitude training, greater heights in competitive sports are hardly ever used. Otherwise occurs as a negative side effect to a too strong reduction in the intensity of training. Most will be trained on a much lower level, often in the range between 1,900 m and 2,500 m. In alpinism, particularly in high-altitude mountaineering, however, acclimatization to much greater heights may be useful and necessary, since usually lower stress intensities occur and acclimatization to altitude is necessary that never occur in competitive sport.

When choosing the right height and individual characteristics of the athlete such as are his previous Hypoxieerfahrung considered.

Frequency and duration

Most stays are recommended by several weeks for meaningful altitude training. Frequently repetitions of Hypoxietrainings be considered to be favorable, but it is also believed that too frequent height stays could be counterproductive. The choice of the right time for Hypoxietrainingsphasen is also important.

Exercise intensity

Frequently at altitude training with the same intensity is difficult. Most is therefore recommended to increase the load only after several days of acclimatization to the usual extent.