Altitude training has been observed to potentially enhance sea level performance in endurance athletes. The phenomenon was first noticed after the 1968 Olympics in Mexico City, which was situated at an altitude of 7600 feet. Some athletes experienced improved performance upon their return to sea level, while others did not notice any difference. Studies have indicated that runners who trained at 6,000 feet for ten days and then performed at low altitude exhibited improved aerobic power. The lower oxygen levels at altitude stimulate the production of erythropoietin (EPO), resulting in an increase in red blood cells or hematocrit, facilitating the transportation of more oxygen to the tissues. Essentially, this natural process can be likened to blood doping.

Recent studies have further explored the benefits of ‘training low’ and ‘sleeping high’ approaches. Athletes are utilizing hypoxic tents equipped with oxygen extractors to create a moderate altitude environment in which they sleep or lounge for several hours a day. This stimulates erythropoietin production, leading to an increase in hematocrit or red blood cell count. The concept of ‘live high, train low’ has shown promising results, as athletes who lived at altitude and trained at sea level demonstrated improved race times. This approach allows athletes to train more rigorously while optimizing their blood’s oxygen-carrying capacity. However, it is essential for athletes training and sleeping at altitude to ensure they maintain adequate iron stores and nutrition, particularly for women, who may experience lower iron levels due to menstrual blood loss.

Nonetheless, it should be noted that the response to hypoxia and erythropoietin production can vary significantly among individuals. While some athletes may experience substantial benefits from training and/or sleeping at altitude, others may not respond as effectively.

While moderate altitude training offers benefits, there are limitations to consider. Training at altitudes above 8,000 feet is generally not recommended, as exercise capacity decreases, potentially leading to deconditioning. Additionally, recovery time increases at higher altitudes, necessitating longer intervals between training sessions. Furthermore, elevated levels of catecholamines (epinephrine and norepinephrine), the body’s stress hormones, at extremely high altitudes can contribute to weight loss and muscle wasting.