The word aerobic means “with oxygen present”, and any physical exercise that intends to build cardiorespiratory endurance, is known as aerobic training. Training aerobically can be found in several cardiovascular activities such as, cycling, swimming, running, and rowing. The body will undergo metabolic changes during aerobic training and system changes will occur over a prolonged period of time. Some of the adaptations are, increased mitochondria density in slow twitch muscle fibers, higher aerobic capacity, increase in trained muscle capacity to utilize and mobilize fat, and develop greater slow twitch muscle fibers. As a result, aerobic training increases the body’s functional capacity to transport and use oxygen and to burn fatty acids during exercise.