This book is a comprehensive text on cardiorespiratory health. Although the strong association between physical inactivity and disease is well documented, cardiorespiratory disease is increasing worldwide in all age groups and is a greater risk factor in children. Epidemiologic studies have shown an inverse association between cardiorespiratory fitness and coronary heart disease or all-cause mortality in healthy participants. Recent guidelines for the treatment of overweight and obesity include recommendations for risk stratification according to disease conditions and cardiovascular disease risk factors, but the role of physical inactivity is not evident in these recommendations. Cardiorespiratory endurance is the level at which your heart, lungs, and muscles work together when you exercise for long periods. This shows how efficiently your cardiorespiratory system is working and is an indicator of how physically fit and healthy you are. Cardiorespiratory fitness is a major cause of morbidity among athletes of all levels and its prevalence is increasing. Physical fitness is defined as the ability to perform activities of daily living without fatigue, to participate in and enjoy recreational activities, and to have the energy to cope with unexpected situations. Cardiorespiratory fitness is one of the health-related components of physical fitness and is defined as the ability of the heart, lung, and vascular system to deliver oxygen and nutrients to working muscles. Exercisers can improve cardiorespiratory endurance by participating in a regular aerobic exercise program. Improved cardiorespiratory fitness provides many health benefits. Physical inactivity and low cardiovascular fitness are important cardiovascular, metabolic, and mortality risk factors. Studies show the importance of physical activity for improving cardiorespiratory fitness. This book contains nine chapters that provide up-to-date information on cardiorespiratory fitness.