NSCA-CPT Exercise Physiology 5

Question 1

What is the primary function of myoglobin in skeletal muscle?

Accepted Answer

Storing and facilitating oxygen transport within the muscle cell

Answer

Myoglobin stores oxygen within muscle fibers and facilitates its diffusion from capillaries to mitochondria during aerobic metabolism.

Question 2

During steady-state submaximal aerobic exercise, which substrate mix is MOST accurate at moderate intensity (~65% VO2max)?

Accepted Answer

Roughly equal contributions from carbohydrate and fat

Answer

At ~65% VO2max, both carbohydrate and fat contribute approximately equally to energy production, a mix that shifts toward carbohydrates at higher intensities.

Question 3

The sliding filament theory of muscle contraction states that muscle force is generated when:

Accepted Answer

Myosin cross-bridges pull actin filaments toward the center of the sarcomere

Answer

Myosin heads (cross-bridges) bind actin and pivot to pull actin toward the M-line, shortening the sarcomere and generating force without the filaments themselves changing length.

Question 4

Which change in blood chemistry during intense exercise MOST directly stimulates increased ventilation?

Accepted Answer

Increased blood CO2 and decreased pH

Answer

Rising blood PCO2 and falling pH (increased H+ ions) are the primary stimuli detected by central and peripheral chemoreceptors to drive ventilation during intense exercise.

Question 5

Which term describes the heart's ability to stretch and fill with more blood, increasing stroke volume without an increase in end-diastolic pressure?

Accepted Answer

Frank-Starling mechanism

Answer

The Frank-Starling mechanism states that greater ventricular filling (preload) increases myocardial stretch, resulting in a more forceful contraction and larger stroke volume.

NSCA-CPT Exam Practice Test

NSCA-CPT Exam Practice Test

NSCA-CPT Exercise Physiology 5