ACSM Exercise Physiology 3

Question 1

The Fick equation for VO2 is best expressed as:

Accepted Answer

VO2 = HR × SV × (CaO2 – CvO2)

Answer

The Fick principle states that VO2 equals cardiac output (HR × SV) multiplied by the arteriovenous oxygen difference (a-vO2 diff).

Question 2

During maximal aerobic exercise, what is the primary limiting factor for VO2max in most healthy untrained individuals?

Accepted Answer

Cardiac output (oxygen delivery)

Answer

In untrained individuals, maximal cardiac output is the primary limiter of VO2max because it constrains oxygen delivery to working muscles.

Question 3

Which physiological adaptation primarily explains the reduction in resting heart rate seen after 12 weeks of aerobic training?

Accepted Answer

Enhanced stroke volume allowing lower HR for the same cardiac output

Answer

Training increases stroke volume (via cardiac hypertrophy and increased blood volume), so a lower resting heart rate maintains the required cardiac output.

Question 4

What is the primary fuel source during low-intensity exercise at 25% of VO2max?

Accepted Answer

Plasma free fatty acids

Answer

At very low exercise intensities, plasma free fatty acids from adipose tissue lipolysis are the dominant energy substrate.

Question 5

The ventilatory threshold (VT) is identified during a graded exercise test by noting a nonlinear increase in:

Accepted Answer

VCO2 relative to VO2

Answer

VT is detected by a disproportionate rise in VCO2 relative to VO2 (the V-slope method), reflecting buffering of excess lactate by bicarbonate.

ACSM Practice Test

ACSM Practice Test

ACSM Exercise Physiology 3