1. Unit 6, Day 4: Cardiovascular Effects of Training
PSK 4U

2. Take out your mini-lab and graphs:
From Yesterday...
Take out your mini-lab and graphs:
What did you notice about your heart rate as you exercised over time?
What did you notice about your cardiac output?
Any questions?

4. Acute Effects of Exercise
When we begin to move, our skeletal muscles require more fuel (more ATP) which becomes most accessible through cellular respiration
Cellular respiration requires oxygen
Therefore, when we exercise:
HEART RATE increases
STROKE VOLUME increases slightly *see graph
... As a result, CARDIAC OUTPUT increases

5. What enables the increase of SV?
Frank Starling Law: the ability of the heart to stretch and increase the force of the contraction and thus the amount of blood that is ejected.
Similar to stretch in skeletal muscle (skeletal muscle contracts most forcefully when it is slightly stretched longer than resting length)
This is mostly affected by the amount of blood returned to the heart - VENOUS RETURN

6. VENOUS RETURN (VR) increases during exercise by Venoconstriction
The skeletal muscle pump
The thoracic pump
Nervous stimulation (increased HR)

7. Cardiac Output Distribution During Exercise
See p.245 in textbooks

8. What happens with training?
Q (cardiac output)
Rest L/min
Exercise L/min
Stroke volume
Untrained male at rest mL/beat
Highly trained male mL/beat
Highly trained endurance mL/beat
Therefore, with training we can pump out more blood with less beats (HR) which gives a more efficient system.

9. The Cardiovascular Effects of Training
Read pages in your textbooks.
Answer questions on handout!