Physiological responses to exercise at altitude : an update

Area of Science:

• Physiology
• Environmental Medicine
• Exercise Science

Background:

• Recent research has illuminated physiological and metabolic adjustments to high-altitude exposure.
• Key variables studied include heart rate, stroke volume, cardiac output, muscle blood flow, substrate utilization, and mitochondrial function.
• The 'lactate paradox' at high altitude remains an area of significant research interest.

Purpose of the Study:

• To investigate the physiological and metabolic adaptations to short- and long-term high-altitude exposure.
• To explore the mechanisms behind observed alterations in cardiovascular and metabolic functions.
• To understand the role of the sympathoadrenal response in high-altitude acclimatization.

Main Methods:

• Review of studies examining physiological and metabolic responses at rest and during exercise.
• Analysis of factors influencing acclimatization, including hypoxia degree, exposure duration, and exercise intensity.
• Examination of inter-individual variability in adaptation to hypoxic environments.

Main Results:

• High-altitude exposure induces significant physiological and metabolic adjustments.
• A robust sympathoadrenal response is elicited, contributing to critical adaptations.
• Altitude acclimatization influences substrate utilization and mitochondrial function.

Conclusions:

• High-altitude exposure is a significant environmental stressor with profound physiological effects.
• Understanding these adaptations is crucial for optimizing training strategies, such as 'live high-train low' for endurance athletes.
• Individual variability in response to hypoxia necessitates personalized approaches to altitude exposure and training.