ACSM Exercise Physiology 4

Question 1

During resistance exercise, which mechanism accounts for the acute increase in strength observed within the first 4–8 weeks of a training program in untrained individuals?

Accepted Answer

Neural adaptations and improved motor unit recruitment

Answer

Early strength gains (first 4–8 weeks) are primarily due to neural adaptations — improved motor unit recruitment, synchronization, and reduced inhibition.

Question 2

The phosphocreatine (PCr) system can sustain maximal effort for approximately how long before becoming depleted?

Accepted Answer

8–15 seconds

Answer

PCr stores support maximal-intensity exercise for roughly 8–15 seconds before this substrate is largely depleted.

Question 3

At sea level, arterial oxygen saturation (SaO2) in a healthy individual during maximal exercise is typically:

Accepted Answer

95–100%

Answer

In healthy individuals at sea level, SaO2 remains at 95–100% even during maximal exercise because pulmonary gas exchange is usually not limiting.

Question 4

Which cardiovascular variable shows the greatest relative increase from rest to maximal exercise in a trained endurance athlete compared to an untrained individual?

Accepted Answer

Stroke volume

Answer

Endurance training produces cardiac hypertrophy and expanded plasma volume, resulting in a markedly greater trained stroke volume at maximal exercise.

Question 5

Which respiratory adjustment primarily drives the increase in ventilation at the onset of exercise?

Accepted Answer

Neural feedforward signals from the motor cortex and proprioceptors

Answer

The rapid increase in ventilation at exercise onset is driven by central command (motor cortex) and proprioceptive feedback, not by blood gas changes.

ACSM Practice Test

ACSM Practice Test

ACSM Exercise Physiology 4