exercise

• 2 ways how to investigate the effects of exercise:

  • measure breathing rate= how many times their chest rises and falls in a given time
  • measure heart rate= measure pulse= placing 2 fingers on an artery in your wrist or neck and time it
• what do our bodies need when we exercise more?

  • needs to carry out more cellular respiration= all exercise requires muscle movement more than usual
• what do any muscle contractions require?

  lots of energy= gained from respiration
• what does it mean that respiration requires oxygen?

  • needs to get more O2 to our muscles= rate of breathing and volume of each breath is going to have to increase= going to require to move muscles around our lungs more than usual = requires LOTS of energy
• if we exercise more, do we need to pump oxygen around the body more slowly or quickly?


  more quickly than usual= heart rate will increase= requires more energy - can supply enough O2 to all of the muscles and continue to use aerobic respiration - cells will have to use anaerobic respiration due to the lack of O2 to keep up our demands
• what happens during anaerobic respiration?

  lactic acid builds up in our tissues causing burning sensations in muscles after exercise
• what happens after you finish exercising?

  body needs to get rid of all this lactic acid by reacting with oxygen = more lactic acid build up, more oxygen is needed= oxygen debt
• what is oxygen debt?


  amount of extra oxygen the body needs after exercise to react with the accumulated lactic acid and remove it from the cells.
• in anaerobic respiration for reactions to take place what has to happen?

  our RBC carry lactic acid from the muscles over to the liver where it can react with O2 and converted back to glucose
• How does exercise affect the body? Application Task?

  in order to move during exercise - have to contract & relax our muscles.

  muscular contraction requires energy that has to be released by cellular respiration.

  most of the time cells carry out aerobic respiration that is more efficient but requires O2 meaning need to pump oxygen around the body faster when we exercise.

  as a result we increase both our heart & breathing rate