Question

After performing a cardiac re-breathing technique (used to determine cardiac output), you ascertain that an individual cardiac output at maximal exercise was 15 L/min. Which of the following statements is likely True from the information obtained from this test?

a. This individual's stroke volume is likely lower than an apparently healthy individual

b. This individual's V0_2 max (aerobic fitness) was likely greater than an apparently healthy individual of the same age

c. This individual's maximum heart rate is likely greater than an apparently healthy individual of the same age

d. Only A and C are correct

e. None of the above are correct

Answer 1

Answer - A. i.e. This individuals's stroke volume is likely lower than an apparently healthy individual.

Explanation :

Cardiaca output increases from 5 L/min to 20-25 L/min during exercise in untrained individual adn upto 30 L/min in a trained individual.

This individual is having maximal Cardiac output of 15 Liter/min which is much lesser compared to healthy person.

The incresed cardiac output is due to Increase in stroke volume and Heart rate. Of this also Stroke volume has a rectagular relation and platue at a level after which Increase in heart rate is responsible for the increse in cardiac output.

So, as this person is having low maximal Cardiac output, this is due to Low stroke volume and Low maximum heart rate.