B4- Excercise

• What does your body do when you exercise to get enough energy to your cells?

  Your body responds in different ways to get enough energy to your cells.
• Why do muscles need energy from respiration when you exercise?

  Muscles need energy from respiration to contract.
• What happens to your breathing and heart rate when you exercise?

  Your breathing is stepped up and your heart rate increases.
• What is the effect of increased respiration during exercise?

  Increased respiration provides more energy to the muscles.
• How does your body remove CO₂ during exercise?

  CO₂ is removed more quickly from your breathing rate.
• What happens to oxygenated blood during exercise?

  Oxygenated blood increases to get more oxygen into the muscles.
• What occurs when you do vigorous exercises like sprinting?

  Your body can't supply oxygen to your muscles quickly enough.
• What is the consequence of anaerobic respiration in muscles?

  Lactic acid builds up in the muscles.
• What does long periods of exercise cause in muscles?

  Long periods of exercise cause fatigue in the muscles.
• What is an "oxygen debt"?

  An oxygen debt is the amount of extra oxygen needed to react with lactic acid.
• What happens to lactic acid when oxygen is available after exercise?

  Oxygen reacts with lactic acid to form harmless CO₂ and water.
• Why do you have to keep breathing hard after stopping exercise?

  You need to get more oxygen into your blood to repay the oxygen debt.
• What happens to pulse and breathing rate when lactic acid levels are high?

  The pulse and breathing rate stay high while lactic acid levels are high.
• How does the body cope with high levels of lactic acid?

  The blood transports lactic acid to the liver for conversion back to glucose.
• How can you measure breathing rate and heart rate?

  You can measure breathing rate by counting breaths and heart rate by taking the pulse.
• How can you investigate the effect of exercise on the body?

  • Measure breathing rate by counting breaths.
  • Measure heart rate by taking the pulse.
  • Example procedure:

  1. Sit for 5 minutes.
  2. Walk gently for 5 minutes.
  3. Jog slowly for 5 minutes.
  4. Run for 5 minutes.
  5. Plot results in a bar chart.
• What happens to pulse rate as exercise intensity increases?

  Your pulse rate will increase with more intense exercise.
• How can you reduce the effect of random errors in exercise measurement results?

  • Conduct the experiment as a group.
  • Plot the average pulse rate for each exercise.