Question 1

Which energy system is the PRIMARY source of ATP during the first 0–10 seconds of maximal-intensity exercise?

Accepted Answer

The phosphagen (ATP-PC) system, which uses stored ATP and phosphocreatine to rapidly regenerate ATP without oxygen.

Question 2

What is the primary fuel source used by the oxidative energy system during low-to-moderate intensity, long-duration exercise?

Accepted Answer

Free fatty acids (fats) are the primary fuel source, as the oxidative system can efficiently metabolize fat via beta-oxidation during prolonged, lower-intensity activity.

Question 3

At approximately what exercise intensity (percentage of VO2 max) does the body shift from primarily fat metabolism to primarily carbohydrate metabolism?

Accepted Answer

Around 50–65% of VO2 max; above this threshold, carbohydrates become the dominant fuel source as glycolysis becomes more active.

Question 4

What metabolic byproduct of anaerobic glycolysis was historically (and incorrectly) blamed for delayed-onset muscle soreness (DOMS)?

Accepted Answer

Lactic acid (lactate) was historically blamed, but research shows it is cleared within 30–60 minutes post-exercise and is NOT the cause of DOMS.

Question 5

How many net ATP molecules are produced per glucose molecule during anaerobic glycolysis versus aerobic (oxidative) metabolism?

Accepted Answer

Anaerobic glycolysis produces approximately 2 net ATP per glucose; aerobic oxidative metabolism produces approximately 36–38 ATP per glucose.

NASM CPT: Exercise Physiology

Study Modes

Practice Test

Study Guide

Try These Cards

Related Study Decks

NASM Behavior Change

NASM Certified Personal Trainer Exam — Complete Bundle

NASM CPT Functional Anatomy

NASM CPT Nutrition Basics

NASM CPT Special Populations

NASM CPT: Client Assessments

Unlock the Full NASM Certified Personal Trainer Exam Study Bundle