We are going to present one of the most used and typical strategies in cycling and other modalities to improve sports performance., In this case it would be altitude training, which many athletes have been using for some years now., trainers or physiologists to legally improve performance in endurance athletes.

The first studies on training at moderate altitude date back to the middle of the last century., before the Olympic games in Mexico City 1968, where athletes should compete at 2200m, to see its effects on performance at this moderate altitude. Studies are being carried out on the population of the Andean highlands, about some 3500 m. at sea level (Reynafarje, 1962). In them they observed a greater number of myoglobin and oxidative enzymes in the muscles of the people studied who lived continuously at those heights. There are many other studies prior to this competition, that forced scientists and trainers to investigate the effects of height on exercise.

From these studies, many more, specifying already about physical activity and sport, seeing the general adaptations that the human body suffered at different heights. But the main question in all this is: What is it about height that we can't find at sea level? What adaptations does it produce? What is the “bad” thing about training at altitude?

We can answer the first question by saying that At altitude there is the same percentage of oxygen as there is anywhere on our planet., what is less, is the barometric pressure. As we go up there is less pressure (the atmosphere exerts less pressure on the body).
It is for this reason that the oxygen molecule has very little pressure and when it enters, it does so through a pressure gradient with what is already in the body.. Since these air molecules have less pressure, They have less air friction, complicating the entry of oxygen molecules into our lung alveoli.
It is also at this height that the athlete is forced to ventilate more due to the lack of oxygen pressure..

Having said this we can understand that in our body, by having a decrease in this alveolar pressure due to oxygen molecules and an increase in respiratory rate, there is an increase in the production process of red blood cells in our bone marrow, therefore, an improvement in the aerobic response since there is an increase in their production and a greater amount in our bloodstream.

This is the main benefit of staying at altitude, But linking to the second question, it must be said that when an athlete is going to be at altitude, their aerobic performance decreases., As the days go by there is an adaptation and improvement of this (Terraces N, et al. 1990).
On several days of altitude there is an increase in erythropoietin (Richalet and Henry, 2003), noticing a change after several days, since there is an improvement of this protein. This effect is given by the increased production of reticulocytes (small red blood cells) in the bone marrow due to lack of oxygen as described previously (González et al.. 2006)

The effect of erythropoiesiis is very rapid, There are studies that this increase in reticulocyte production is already noticeable after 24 hours of being at altitude., with which there is a decrease in ferritin levels in the athlete since this protein is necessary for the formation of new red blood cells.

Having said this we can give a series of improvements in altitude training and some practical aspects

• Improvement of the oxidative energy pathway and myoglobin.
• Improvement of the oxygen transport component (increased number of red blood cells)
• Improvement of anaerobic capacity by improving muscle buffer capacity.
• Improved ventilation.

Practical aspects of training at moderate altitude (González AJ, et al. 2006) (Calbet JA, et al. 1999)

• Previous stay at altitude, ferritin levels in the blood must be assessed through a blood test, in addition to values ​​​​such as hemoglobin, red blood cells or hematocrit.
• Increase fluid intake, to try to compensate for the decrease in plasma volume that occurs at altitude.
• During the stay you have to individualize and calibrate the training (each athlete has THEIR training and it is better for them to go individually the first days). Training loads must be adjusted very well.
• You have to maintain the rhythm and/or speed and/or frequency, etc.. in altitude training, so as not to lose neuromuscular stimuli.
• We must try to follow the same training planning that would be carried out at that time of year at sea level., both in intensity (for this larger recoveries would be needed), as in quantity (for which perhaps, training sessions need to be divided).
• At altitude fatigue is always greater, rest is very important at altitude, having to increase it in quantity and quality. (plus physical measurements)
• Due to hyperventilation and dry air, The athlete is more prone to pharyngeal and bronchial irritations at altitude, which must be prevented and taken care of.. Since the fatigue is greater, immunity may be somewhat depressed, which will make an infection easier.
• We will have to focus on training fundamentally a single metabolic quality. For this reason, the objectives of each stay at altitude must be very clear..
• Try to do one or more “test” stays at altitude, in order to know the individual responses of the athletes, and their greater or lesser predisposition to adverse symptoms. We also, the more times it has gone to height, in advance, the easier the adaptation.

These are general aspects of staying at altitude, There are many more and they could be specified much better since at a physiological level, altitude training has many more complexities..
As we can see, the effects on the performance of the aerobic athlete (cyclist, runner, triathlete…) are important, but as I said before, It is necessary to do trial stays before a long and definitive one to be able to check whether the athlete responds to the altitude or not (he tolerates the altitude well and adaptations arise or they do not arise)..

Stays at altitude are recommended for a period minimum of 10 days to a maximum of 24-28 days in order to be able to see changes in the athlete's performance, with a set-up period prior to the competition of between 5 to 12 days, depending on each athlete and the duration of the previous stay. (Terraces N, 1995)

Literature

• Calbet JA, González - Alonso J & Nielsen B. Metabolic and thermodynamic responses. Todehydration – induced reductions in muscle blood flow in exercising humans. J. Physiol 520 Pt 2, 577-589. (1999)
• González AJ, Hernandez D, From Vera to, Barrios. Y, Left. E, Torres A, Terraces N. ACE gene polymorphism and erythropoiietin in endurance athletes at moderate altitude. Med Sci Sports Exerc 38(4): 688-93 (2006)
• Reynafarje B. Myoglobin content and enzymatic activity of muscle and altitude adaptation. J Appl Physiol 17, 301-305 (1962)
• Richalet JP & Henry JP. Mountaineering and mountain sports medicine. Masson, Paris. (2003).
• Terraces N, Jansson E, Sylven C. &. Kaijser L. Is hipoxia a stimulus for synthesis of oxidative enzymes and myoglobin? J Appl physiol. 68, 2369 – 2372 (1990).
• Terraces. N. Altitude training and muscular metabolism. Int J Sports Med 13 Suppl. 1, S206-209 (1992).