BIOMOLECULAR ADAPTATIONS AND BIOMARKER DISCOVERY IN CARDIORESPIRATORY ENDURANCE

Abstract

Cardiorespiratory endurance is widely recognized as one of the most important components of physical fitness and a fundamental determinant of human health, athletic performance, and quality of life. It reflects the integrated capacity of the cardiovascular, respiratory, hematologic, and musculoskeletal systems to efficiently deliver, transport, and utilize oxygen during prolonged physical activity. Individuals with higher levels of cardiorespiratory endurance demonstrate superior exercise performance, improved physiological resilience, reduced risk of chronic disease, and increased longevity. Consequently, cardiorespiratory fitness has become a major focus in exercise science, exercise physiology, rehabilitation medicine, and preventive healthcare.

Over the past few decades, the assessment of cardiorespiratory endurance has relied primarily on physiological indicators such as maximal oxygen uptake (VO₂max), heart rate recovery, pulmonary function, lactate threshold, and exercise tolerance. Among these measures, VO₂max is widely regarded as a key physiological indicator of aerobic capacity and cardiorespiratory fitness because it integrates the functional capacity of the cardiovascular, respiratory, circulatory, and skeletal muscle systems to transport and utilize oxygen during maximal exercise. Direct measurement of VO₂ during graded cardiopulmonary exercise testing remains the reference method for assessing cardiorespiratory fitness, although the distinction between VO₂max and VO₂peak should be recognized when a physiological plateau cannot be demonstrated.