Altitude Training for Improved Cycling Performance
Breathing in the thin air of high elevation can help you improve your performance.
Whether you?re planning on ascending high into the Alps or <?xml:namespace prefix = st1 ns = "urn:schemas-microsoft-com:office:smarttags" /?>
The Physiology of Altitude
As we ascend in altitude, there is a drop in barometric pressure that is associated with a decrease in the partial pressure of oxygen. This starts a cascade of decreasing oxygen pressures in the lungs, arteries, capillaries, and, eventually, tissues. The end result is an insufficient supply of oxygen to tissues (hypoxia) that is especially apparent during exercise when the oxygen demands of working muscle increase. Because the oxygen cost of work at altitude is unchanged from that at sea level, to train or compete at the same absolute power requires adaptations that overcome or minimize this decrease in oxygen supply.
In general, all the various systems of the body respond and adapt to the hypoxic stress of altitude. Some of these adaptations have the potential to enhance endurance performance, while other changes may actually hinder it.
The body?s initial response to altitude is to increase breathing rate and heart rate at both rest and during submaximal exercise. In addition, blood is concentrated by reducing the fluid or plasma component. Collectively, these changes improve oxygen uptake by the lungs and its delivery to tissues. The disadvantages of these changes are that perceived exertion at any workload is increased and circulating blood volume is reduced.
With prolonged altitude training and continued acclimatization further adaptations take place. Perhaps the most sought after altitude adaptation results from kidney hypoxia that stimulates release of erythropoietin (EPO). In turn, EPO stimulates red bone marrow to increase production and release of new red blood cells (RBC). This increase in circulating RBCs leads to enhanced oxygen carrying capacity of blood and, therefore, improved oxygen delivery to tissues. At the same time, blood plasma volume increases so that overall blood volume rebounds toward sea level values.
Why We Train at Altitude
Altitude training can be an effective way of improving your cycling performance, at any elevation. Both acclimatization to altitude and training at altitude have been shown to stimulate the following adaptations:
? enhanced oxygen uptake in the lungs
? increased red blood cell numbers to improve oxygen delivery to tissues
? skeletal muscle changes which improve oxygen use by muscle
? increased buffering capacity to possibly delay the onset of fatigue
Taken together, these adaptations improve cycling endurance, sustainable power, and speed. By increasing the amount of oxygen your muscles can get and utilize, altitude training increases the amount of work you can perform before you reach your maximum sustainable power, as well as the work you can sustain when you get there. When you?re