exercise

• muscles need energy to contract, so when you exercise muscles contract more frequently than normal so more energy needed, this energy comes from increased respiration
• increase in respiration in your cells means that you need to get more oxygen in them
• breathing rate + breath volume increases to get more oxygen in them, heart rate increases to get this deoxygenated blood around faster - to remove CO2 more quickly
• when you do vigorous exercise your body cant supply oxygen to your muscles fast enough so they respire anaerobically, this is not the best way to transfer energy from glucose because lactic acid builds up in your muscles which becomes painful
• long periods of exercise cause muscle fatigue - muscles become tired and cannot contract as effectively
• anaerobic respiration leads to oxygen debt

  • oxygen debt is the amount of energy your body needs to react with the building up of lactic acid remove it from cells
• breathing hard after you stop to get more oxygen into blood which is transported to the muscle cells