Aerobic exercise
- Aerobic means "with oxygen". It is used when exercise is at a low to moderate intensity and lasts a long time, such as a marathon.
- Aerobic respiration: glucose + oxygen → energy + carbon dioxide + water.
- The heart and lungs can supply enough oxygen for the demand, so there is no build-up of lactic acid.
Anaerobic exercise
- Anaerobic means "without oxygen". It is used for short, high-intensity bursts, such as a 100 m sprint or a shot put.
- Anaerobic respiration: glucose → energy + lactic acid.
- Lactic acid builds up in the muscles and causes fatigue, so anaerobic exercise can only last a short time.
- Most sports use both: a footballer jogs aerobically but sprints anaerobically.
EPOC (oxygen debt)
- EPOC (excess post-exercise oxygen consumption) is the extra oxygen taken in after exercise to recover.
- It explains why breathing and heart rate stay high after hard exercise.
- The extra oxygen is used to break down lactic acid and restore the body to its resting state.
Recovering from exercise
- Cool down: keeping breathing and heart rate raised helps remove lactic acid and reduces muscle soreness.
- Diet: rehydrating with water or sports drinks, and eating carbohydrates to refuel.
- Ice baths and massage reduce swelling and help blood flow to remove waste.
Key terms
- Aerobic
- Using oxygen to release energy; for long, low to moderate intensity exercise.
- Anaerobic
- Releasing energy without oxygen; for short, high-intensity exercise.
- Lactic acid
- A waste product of anaerobic respiration that causes fatigue.
- EPOC
- Excess post-exercise oxygen consumption: the extra oxygen needed to recover after exercise.
- Oxygen debt
- Another name for EPOC.
- Glucose
- The sugar that is broken down to release energy.