Aerobic refers to processes that require oxygen to occur. In biology, aerobic respiration is a method by which cells convert glucose and oxygen into energy, carbon dioxide, and water. This process is essential for the survival of many organisms, including humans, as it provides the energy needed for various bodily functions. In fitness, aerobic exercise involves activities that increase heart rate and breathing while using large muscle groups. Examples include running, swimming, and cycling. These exercises improve cardiovascular health, enhance endurance, and promote overall well-being by increasing the efficiency of the heart and lungs in delivering oxygen to the body.