Cardiac Output Worksheet
Heart Rate (HR) = the number of heart beats (contractions) per minute (bpm)
Stroke Volume (SV) = the volume of blood pumped from the left ventricle per beat (ml/beat)
- Approximate resting value in adults = 70ml
- Approximate value during exercise in adults = 110-120ml
Cardiac Output (Q) = the volume of blood ejected from the left ventricle per minute (L/min)
Resting HR = ________
Working HR = ________ (after 1min of jumping jacks)
Cardiac Output (Q) = Stroke Volume (SV) x Heart Rate (HR)
* The following questions will use the approximate values for SV given above, combined with the
HR values you’ve filled in above.
Resting HR
= ____________
Working HR = ____________
Resting SV
= 70ml
Working SV = 120ml
Resting Q
= ____________
Working Q
= ____________
Approximately _______liters of blood need to be pumped around the body to supply the O2 the body
needs at rest (cardiac demand). Aerobic training can cause the resting HR to decrease. This is due to
an increased SV, meaning a lower HR is needed to meet the cardiac demand.
Take 10 beats away from your resting HR and calculate how the SV changes if Q is maintained.
_________
Resting Q
= _____________ x
Resting HR – 10
_________
New SV
(SV = Q/HR)
Suggest why the SV has increased below:
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A trained heart does not have to beat as many times as an untrained heart to produce the same
cardiac output. What effect will this have on maximal cardiac output?
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Calculate: Your maximal cardiac output (during exercise) assuming you were a highly trained
endurance athlete. Show your working below.
- Maximal HR = 220 – age
- SV of highly trained endurance athlete ~ 170ml
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