Moderate Normobaric Hypoxia Does Not Exacerbate Left Ventricular Dysfunction After Exhaustive Exercise in Athletes...

Area of Science:

• Sports Medicine
• Cardiology
• Physiology

Background:

• Hypoxia exposure is used for training adaptations, but its acute cardiac effects are unclear.
• Exercise-induced cardiac fatigue (EICF) involves transient left ventricular (LV) systolic and diastolic dysfunction.
• The impact of moderate hypoxia on EICF, especially in athletes, requires investigation.

Purpose of the Study:

• To investigate the acute effects of moderate normobaric hypoxia on EICF in endurance-trained athletes and untrained individuals.
• To compare cardiac function responses to exhaustive exercise under normoxia and hypoxia.

Main Methods:

• Twenty-four men (12 trained cyclists, 12 untrained) underwent exhaustive cycling tests.
• Tests were conducted under normoxia (20.9% O2) and moderate hypoxia (14.4% O2, ~3000 m).
• Echocardiography assessed LV systolic and diastolic function at rest and post-exercise.

Main Results:

• Exhaustive exercise impaired LV diastolic function similarly in both conditions and groups.
• LV GLS showed less negative values post-exercise, indicating systolic impairment.
• Athletes demonstrated slightly less systolic impairment under hypoxia compared to normoxia (p < 0.05).

Conclusions:

• Moderate normobaric hypoxia (~3000 m) does not exacerbate EICF.
• Athletes may experience reduced post-exercise systolic impairment under moderate hypoxia.
• Further research with larger cohorts and preload assessment is needed to confirm hypoxia's cardiac effects.