Exercise

 

You need to understand how the body responds to exercise in terms of oxygen and respiration. When exercising, the body must increase oxygen delivery to keep respiration occurring.

 

Ways through which the body increases oxygen delivery around the body:  

1. Heart rate ↑  

2. Breathing rate ↑  

3. Breath volume ↑

 

If oxygen runs out:  

• Switch to anaerobic → lactic acid builds up

• Lactic acid is toxic to the body and needs oxygen to break it down again.  

• Oxygen debt = extra O₂ needed after exercise to:  

  • Convert lactic acid → glucose in liver  

  • Restore energy stores

 

(HT) Muscle fatigue from lactic acid

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Metabolism

 

Metabolism = sum of all chemical reactions in a cell/body

 

Energy from respiration powers:  

• Glucose → starch/glycogen/cellulose  

• Glycerol + fatty acids → lipids  

• Glucose + nitrates → amino acids → proteins  

• Excess protein → urea (excreted in urine)

 

All these chemical reactions together contribute to the body's overall metabolism. The body will carry out each of these processes at different times depending on what the body needs at that specific time.