The prevalence of non-communicable diseases (NCDs) has been rising globally, and physical inactivity is one of the major risk factors of NCDs. Increasing physical activity helps prevent and treat a variety of NCDs and improve overall health. Regular exercise promotes efficiency of oxygen delivery by heart, lung and general circulatory system in general, improves cardiorespiratory fitness, and reduces resting heart rate. This article used keywords like physical activity, exercise, mortality, cardiorespiratory fitness, and resting heart rate to identify in Google Scholar related papers published in academic and scientific journals. After reviewing, analyzing, and critically assessing the results and conclusions of the identified papers, we confirmed the effectiveness of increasing physical activity in promoting overall health and lowering risks of various NCDs morbidity and mortality by improving cardiorespiratory fitness, and decreasing resting heart rate. Physical activity, cardiorespiratory fitness, and resting heart rate can therefore be used as important indicators of overall health. Our study further suggests that the optimal physical activity volume should be 5 times of the minimal level recommended by WHO, i.e., moderate-intensity exercise for 150 minutes per week. The best cardiorespiratory fitness level and resting heart rate, on the other hand, are recommended to be higher than 14 metabolic equivalent of task and lower than 50 beats per minute respectively.