Exercise

• Why do humans need energy?

  For movement, warmth, and chemical reactions
• Why do we not need much energy when relaxing?

  Because we are not moving
• What happens to energy demand during exercise?

  It increases for muscle contraction
• How does aerobic respiration change during exercise?

  It increases to meet energy demands
• What happens to breathing rate and volume during exercise?

  Both increase to supply more oxygen
• Why does heart rate increase during exercise?

  To pump oxygenated blood around the body
• What problem can occur during intense exercise?

  Not enough oxygen can be supplied to muscles
• What occurs when there is insufficient oxygen during exercise?

  Anaerobic respiration takes place in muscles
• What is produced during anaerobic respiration?

  Lactic acid is produced in the muscles
• What effect does lactic acid have on muscles?

  It causes muscle fatigue and inefficient contraction
• What must the body do with lactic acid after exercise?

  Remove lactic acid from the muscles
• What condition is created by the buildup of lactic acid?

  Oxygen debt
• What happens to lactic acid after it is transported out of the muscles?

  It is converted back to glucose in the liver
• Why does the body need extra oxygen after exercise?

  To deal with accumulated lactic acid
• Why do people continue breathing rapidly after exercise?

  To supply oxygen for lactic acid removal
• What happens in the body during exercise?

  • Increased energy demand for muscle contraction
  • Increased aerobic respiration for energy
  • Increased breathing rate and volume for oxygen
  • Increased heart rate to pump oxygenated blood
  • Possible insufficient oxygen supply leading to anaerobic respiration
  • Production of lactic acid causing muscle fatigue
  • Removal of lactic acid creates oxygen debt
• What is oxygen debt?

  • Extra oxygen needed after exercise
  • Required to remove accumulated lactic acid
  • Causes continued rapid breathing post-exercise