SCI Energy Systems & Exercise Physiology

Question 1

Which of the following correctly identifies the three primary energy systems used during exercise?

Accepted Answer

Phosphagen, Glycolytic, and Oxidative

Answer

The three primary energy systems are the phosphagen (ATP-PCr), glycolytic (lactic acid), and oxidative (aerobic) systems, each dominating at different exercise intensities and durations.

Question 2

Which energy system provides ATP most rapidly but is limited to only 8–10 seconds of maximal effort?

Accepted Answer

Phosphagen (ATP-PCr) system

Answer

The phosphagen system uses stored ATP and phosphocreatine to generate energy almost instantaneously but is depleted within 8–10 seconds of all-out effort.

Question 3

At low-to-moderate exercise intensities, the aerobic energy system primarily relies on which substrate?

Accepted Answer

Fat (free fatty acids)

Answer

At low-to-moderate intensities, fat (free fatty acids) is the predominant fuel for the aerobic energy system due to its high energy yield per gram.

Question 4

VO2 max is best defined as the:

Accepted Answer

Maximum rate of oxygen consumption during intense exercise

Answer

VO2 max is the maximal rate at which the body can consume and utilize oxygen during intense exercise, and is the gold standard measure of aerobic capacity.

Question 5

The lactate threshold is best described as the exercise intensity at which:

Accepted Answer

Blood lactate concentration rises faster than it can be cleared

Answer

The lactate threshold is the point where lactate production exceeds the body's clearance capacity, causing blood lactate to accumulate and signaling a shift toward anaerobic metabolism.

SCI - Stages Cycling Instructor Certification Practice Test

SCI - Stages Cycling Instructor Certification Practice Test

SCI Energy Systems & Exercise Physiology