Altitude Training: Physiological Risks, Performance Limitations, and Practical Drawbacks

What are the negatives of altitude training?

While altitude training offers potential physiological benefits for endurance athletes, it also presents significant challenges and risks, including acute physiological stress, reduced training capacity, and practical logistical hurdles that can impede performance and health.

Altitude training, a strategy employed by athletes to enhance endurance performance, leverages the body's adaptive responses to hypoxia (reduced oxygen availability). While the aim is to stimulate erythropoiesis (red blood cell production) and improve oxygen transport, the environment itself imposes considerable stress and numerous drawbacks that must be carefully considered.

Physiological Challenges and Health Risks

Training or living at altitude places the body under immediate and profound physiological stress, leading to several potential negative health outcomes:

• Acute Mountain Sickness (AMS): This is the most common altitude-related illness, typically occurring within 6-12 hours of arrival at altitude. Symptoms include headache, nausea, vomiting, dizziness, fatigue, and difficulty sleeping. While generally mild, it can severely impair training quality and enjoyment.
• High Altitude Pulmonary Edema (HAPE): A more severe and potentially life-threatening condition where fluid accumulates in the lungs, impairing oxygen exchange. Symptoms include severe shortness of breath at rest, persistent cough, chest tightness, and extreme fatigue. It requires immediate descent and medical attention.
• High Altitude Cerebral Edema (HACE): The most severe form of altitude sickness, involving swelling of the brain. Symptoms include severe headache, confusion, loss of coordination (ataxia), altered mental status, and potentially coma. HACE is a medical emergency requiring immediate descent and treatment.
• Increased Cardiovascular Strain: The body compensates for reduced oxygen by increasing heart rate and cardiac output, placing additional stress on the cardiovascular system. This can be particularly risky for individuals with pre-existing heart conditions.
• Dehydration and Electrolyte Imbalance: The dry air at altitude, coupled with increased respiratory rate and diuresis (increased urine production), leads to greater fluid loss. This increases the risk of dehydration, which can impair performance and exacerbate AMS symptoms.
• Immune System Suppression: Prolonged exposure to altitude stress, combined with intense training, can suppress the immune system, making athletes more susceptible to infections and illnesses.
• Sleep Disturbances: Many individuals experience disrupted sleep patterns at altitude, including frequent waking, vivid dreams, and Cheyne-Stokes breathing (a pattern of waxing and waning respiration), which further compromises recovery and overall well-being.

Performance Impairment and Training Limitations

Paradoxically, the very environment designed to enhance performance can initially hinder it, leading to a period of reduced training quality and potential detraining:

• Reduced Training Intensity and Volume: During the initial acclimatization phase, athletes must significantly reduce their training intensity and volume. Attempting to maintain sea-level workloads at altitude can lead to overtraining, injury, or severe altitude sickness. This means a temporary dip in performance metrics.
• Slower Recovery Times: The hypoxic environment, combined with increased physiological stress, can prolong recovery periods between training sessions. This limits the frequency of high-quality workouts.
• Muscle Mass Loss (Catabolism): Some studies suggest that prolonged exposure to high altitude, especially when combined with insufficient caloric intake, can lead to muscle catabolism (breakdown). This is due to increased metabolic rate, appetite suppression, and the body's stress response.
• Difficulty with Nutrition: Altitude can suppress appetite and alter taste perception, making it challenging for athletes to consume adequate calories and nutrients necessary to support training and recovery.
• Detraining Upon Return to Sea Level: While the "Live High, Train Low" (LHTL) model aims to mitigate this, simply living at altitude and then returning to sea level without proper tapering or continued high-intensity training can lead to a rapid loss of altitude adaptations, potentially negating the benefits.

Practical and Logistical Drawbacks

Beyond the physiological, altitude training presents significant practical and logistical hurdles that can make it unfeasible or undesirable for many athletes:

• High Cost: Traveling to and residing in high-altitude locations, or investing in artificial altitude simulation equipment (hypoxic tents, chambers), can be prohibitively expensive.
• Time Commitment: A minimum of 2-4 weeks is typically required for meaningful acclimatization and adaptation, which is a substantial time commitment that can disrupt an athlete's regular training schedule, work, or family life.
• Logistical Complexity: Arranging travel, accommodation, appropriate training facilities, and access to medical support in remote high-altitude areas can be complex and challenging.
• Disruption of Routine: Being away from one's regular training environment, coaches, support staff, and familiar nutrition options can be disruptive and stressful.
• Variable Individual Response: Not all athletes respond equally well to altitude training. Some individuals may experience significant benefits, while others may struggle with acclimatization and achieve minimal or no performance gains, making the investment of time and money uncertain.

In conclusion, while altitude training holds allure for its potential to enhance endurance, it is a demanding strategy fraught with physiological risks, training limitations, and considerable practical obstacles. Athletes considering this approach must undergo thorough medical screening, adhere to a carefully planned acclimatization schedule, and be prepared for a challenging experience that may not yield guaranteed benefits.