1. Effect of Exercise on Gas Exchange

2. Important Terms and Formulas
Minute ventilation
Tidal volume
Oxygen Uptake/Volume of Oxygen (VO2)
Volume of Carbon Dioxide (VCO2)
Minute ventilation = Breaths/min x tidal volume
VO2 = minute vent. x (% inhaled O2 - % exhaled O2)

3. Activity
In this activity we are going to examine the effect that exercise has on the respiratory system

4. Activity
Before we start, we must realize that we are limited slightly by the equipment (or lack of equipment) that we have. So in order to make some calculations, we will have to make a few assumptions. Here they are:
Resting tidal volume = 500 ml
Exercising tidal volume = 1000 ml
Composition of Inhaled Air = 21% Oxygen, .039 % CO2
Composition of Exhaled Air = 16 % Oxygen, 5% CO2

5. Part 1 Resting: Select a group member
Have them sit in a chair and relax for 1 minute
Count the number of breaths they have in 1 minute and record.
Using the assumptions on the previous page, calculate the amount of Oxygen getting into their body in 1 minute. This is called their minute ventilation

6. Part 2
Exercise:
The subject will stand in front of a chair and step up and down on the chair for two minutes at the pace Mr. Herb controls.
Another person in the group will hold the chair in place so it does not move.
As soon as he/she is finished, count the number of breaths he/she takes in 30 seconds and multiply by two to get breaths per minute.
Calculate minute ventilation after exercise

7. Results Complete this table as a class Name Resting Breath Rate
Minute Ventilation
Resting VO2
Hazlini 20
10 L
500 ml
Dung 24
12 L
600ml
Mark 13
6.5 L
325 ml
Monica 18
9 L
450 ml

8. Exercise Breathing Rate
Exercise Results
Name
Exercise Breathing Rate
Minute Ventilation
Exercise VO2
Hazlini 69
69 L
3.45 L/min
Dung 39
39 L
1.95 L/min
Mark 24
24 L
1.2 L/min
Monica 54
54 L
2.7 L/min
Average

9. Analysis What effect did exercise have on breathing rate?
What effect did exercise have on VO2? Why?
Why is it important for athletes to be able to take a lot of oxygen into their body?
Extension
Which way does CO2 go during breathing?
Calculate the VCO2 for rest and exercise just like you did for VO2.
Describe the effect of exercise on VCO2.