Why Does Altitude Training Work?

Let’s get into the science a little bit. While it can seem complicated, the mechanism by which altitude training works is simple. In sports, the key limiting factor to success is the athlete’s ability to carry and metabolize oxygen in the course of a competition. Because oxygen is the primary source of energy production for human cells, exposure to altitude or hypoxia (reduced oxygen levels) introduces a new challenge that the body must confront and adapt to in order to maintain balance.

Under a state of hypoxia, the body strives to produce the required amounts of energy with less oxygen available. Exposure to hypoxia stimulates upregulation of Hypoxia Inducible Factor (HIF-1), which promotes an improvement of the body’s oxygen utilization system at every link in the chain. Initially, lung oxygen absorption is enhanced to allow more oxygen to enter the system. At the same time, the kidneys signal for an increase in Erythropoietin Hormone (EPO), which stimulates the production of red blood cells (RBCs) and hemoglobin. An increase in RBCs and hemoglobin provide an increased number of vehicles for transportation of oxygen throughout the body.

At the next level, certain growth factors (VEGF) trigger increased capillarization. Capillaries are the smallest yet arguably most important blood vessels in the body, and increasing their size and number significantly improves oxygen delivery to tissues, muscles and brain. More blood pathways to cells equates to richer oxygenation and more energy availability.

Finally, hypoxia causes a boost in production and rejuvenation of mitochondria, which are the body’s principle source of aerobic energy production within cells. Increasing mitochondria and mitochondrial enzymes allows more efficient use of oxygen for energy production and enhanced enzymatic anti-oxidative defense. In short, altitude training improves our body’s ability to efficiently carry and deliver oxygen from the lungs to the blood to the working muscles needed for performance. Because oxygen availability is critical for our body’s ability to perform, improving the body’s capacity to carry and utilize oxygen is significantly correlated with improved performance.

In addition to basic acclimatization to altitude, benefits of altitude training include:

• Amplified pulmonary oxygen absorption.

• Increased O2 uptake and delivery (VO2max) for enhanced power output and increased speed, strength and endurance.

• Boosted production of Erythropoietin Hormone (EPO) by the kidneys, stimulating generation of Red Blood Cells (RBCs) and enhanced oxygen transportation through the body.

• Increased capillarization for greater oxygen delivery to the tissues, muscles and brain.

• Enhanced production and rejuvenation of mitochondria allowing more efficient utilization of oxygen.

• Decreased average heart rate and blood pressure.

• Increased production and release of human growth hormones.• Stimulation of fat metabolism (discussed more later).