response to excercise

• What happens to respiration when we exercise?

  Respiration rate increases as our cells require more energy.
• What happens to heart rate when respiration increases?

  Heart rate increases so that blood circulates faster. This helps supply more oxygen and glucose to muscle cells (and removes lactic acid more quickly too).
• What happens to breathing rate when respiration increases?

  Breathing rate increases so that more oxygen enters the blood. This also helps supply more oxygenated blood to muscle cells (and removes carbon dioxide more quickly too).
• What happens to breath volume when respiration increases?

  Each breath volume is bigger as we breathe more deeply during exercise. This also helps supply more oxygenated blood to muscle cells.
• What if not enough oxygen gets to muscle cells?

  Anaerobic respiration will start to take place (as well as aerobic, with whatever oxygen is delivered to muscle cells). Lactic acid levels will start to build up, creating an oxygen debt.
• What is the problem with lactic acid build up?

  Cells become fatigued if there is too much lactic acid produced. They stop contracting efficiently.
• What happens to the lactic acid?


  Blood flowing through the muscles transports lactic acid to the liver where it is converted back into glucose. Oxygen debt is the amount of oxygen needed to react with the lactic acid and remove it.