Exercise

• When exercising energy from respiration is used to contract muscles and the breathing rate and breath volume increase to get more oxygen into the blood : heart rate also increases to get oxygenated blood around the body faster
• When the body cannot supply enough oxygen it starts respiring anaerobically which released lactic acid which is painful : long periods of exercise leads to muscle fatigue and muscles stop contracting effectively
• After anaerobic respiration the body will have and oxygen debt which is needed to remove lactic acid from the cells
• Blood can enter muscles and transport lactic acid to the liver where it is converted back to glucose