Excercise

• What happens when you exercise

  1. Muscles need energy from respiration to contract

  2. Increased respiration in cells means need more oxygen

  3. Breathing rate and breath volume increase to get more oxygen

  4. Heart rate increases to get oxygenated blood around body faster

  5. Body can't supply oxygen quickly enough, so start anaerobic respiration

  6. Anaerobic respiration leads to lactic acid build up and muscle fatigue
• Anaerobic respiration


  Respiration without oxygen, leads to lactic acid build up
• Oxygen debt


  1. Body needs extra oxygen to react with lactic acid and remove it

  2. Have to keep breathing hard to get more oxygen into blood

  3. Pulse and breathing rate stay high while high levels of lactic acid and CO2
• Lactic acid


  Transported to liver and converted back to glucose
• Investigating effect of exercise on body

  1. Measure breathing rate by counting breaths

  2. Measure heart rate by taking pulse

  3. Pulse rate increases with more intense exercise
• To reduce effect of random errors, do experiment as a group and plot average pulse rate