Exercise intensity refers to how hard your body is working during physical activity. It can be measured in various ways, such as heart rate, perceived exertion, or the amount of weight lifted. Higher intensity workouts, like sprinting or heavy weightlifting, require more effort and energy compared to lower intensity activities, such as walking or light stretching. Understanding exercise intensity is important for achieving fitness goals. For example, cardiovascular training often involves moderate to high intensity to improve heart health, while strength training may focus on varying intensities to build muscle. Balancing different intensities can enhance overall fitness and prevent injury.