Answer: Heart strength and healthy circulatory system
Step-by-step explanation:
Fatigue is considered to be the state in which a person cannot maintain the level of performance or training expected. Muscles are able to obtain energy by aerobic or anaerobic respiration and both use carbohydrates or sugars, but only aerobics needs oxygen. To perform physical activity, the heart pumps more oxygen to the muscles that are performing the exercise. When the muscles work harder, the body consumes more oxygen and produces more carbon dioxide. So, aerobic respiration is a type of metabolism in which the organism uses energy from organic molecules, especially as glucose, where the carbon is oxidized by the oxygen. 36 molecules of ATP per glucose are produced during aerobic respiration.
During an effort, the energy produced by aerobic breathing is not enough and muscles need to produce a complementary energy through anaerobic respiration which provides less energy than aerobic respiration. This type of cellular respiration produces waste products that the cells must eliminate, for example lactic acid, which remains in the muscles producing pain after exercise. Only 2 molecules of ATP are produced for each glucose during anaerobic respiration.
Therefore, the heart strength is important because that organ is responsible for carrying oxygen to the muscles, which is needed to perform cellular respiration and get more energy to perform the exercise. And there must be also a healthy circulatory system that delivers that oxygen to every part of the body.