By measuring the pulse rate, we can detect the increasing heart rate. The stroke volume also increases which is the volume of blood pumped in each beat. We can calculate the total cardiac output using the equation below:Cardiac output = stroke volume x heart rateBoth aerobic and anaerobic respiration takes place during hard exercise as the oxygen supply may not be enough for the needs of the muscle cells. An oxygen debt builds up which is known as Excess Post-exercise Oxygen debt (EPOC). This is when glucose is not completely broken down to form carbon dioxide and water. Some of this glucose is broken down to form lactic acid. Breathing heavily after exercise provides oxygen to break down lactic acid. It is also broken down by the liver. Lactic acid is carried away by the blood to the liver when the heart rate is increased. During exercise, the pH of the blood is decreased as the concentration of carbon dioxide is increased in the blood and respiring tissues. The low pH makes the blood more acidic which can cause acidemia and if prolonged, causes acidosis. It is the disease in which the body cells are injured by a rise in acidity that can lead to failing functions of the heart for example; low blood pressure and cardiac arrhythmia. Carbon dioxide is known as an asphyxiant. It bonds with your blood in place of oxygen. It can damage the central nerve system and can cause permanent deterioration of respiratory functions. Excess of lactic acid in the body can cause lactic acidosis. People with this disease have kidneys that are unable to remove excess acid. It causes nausea and weakness. The bicarbonate buffer system in the blood is an acid-base homeostatic mechanism that maintains the pH in the blood and duodenum to support proper metabolic function. Most of the carbon dioxide produced by cellular respiration is rapidly removed from the tissues by its hydration to bicarbonate ion. This bicarbonate ion is transported to the lungs, where it is dehydrated back into CO2 and released during exhalation. B3 Factor that can affect respiration Cigarettes:Activities and environment that can affect the respiratory system such as exercise, drugs.Inhalation of cigarettes can affect respiratory systems as it declines lungs function. Therefore lungs does not work as efficient as they should which is why smoker face difficulty while exercising as their lungs can not carry enough oxygen. Narrowing of airway and excessive mucus production causes permanent damage to lungs. Nicotine is inhaled chemical found in cigarettes which is highly addictive. Tar is another chemical found in cigarette which paralyzes cilia in the trachea and contributes to lung disease such as emphysema, chronic bronchitis and lung cancer. Cigarette tar is a poisonous and carcinogenic chemical present in tobacco smoke. The best way to avoid this is to avoid smoking as well as the indoor places with excessive cigarette smoke.