EXPH 386 Exam 2 REAL EXAM QUESTIONS WITH
100% RATED CORRECT ANSWERS (ACCURATELY
PASSED) 2026 LATEST UPDATED GET A+
1–10: Energy Systems & Metabolism
1. Which energy system predominates during a 100-meter sprint?
A. Oxidative
B. Glycolytic
C. ATP-PCr
D. Aerobic
Rationale: Short, maximal-intensity efforts rely on the ATP-phosphocreatine system for
immediate energy.
2. The glycolytic system primarily produces ATP through:
A. Aerobic metabolism
B. Anaerobic breakdown of carbohydrates
C. Phosphocreatine hydrolysis
D. Fat oxidation
Rationale: Glycolysis breaks down glucose anaerobically to generate ATP for high-intensity
activity lasting 30 seconds to 2 minutes.
3. During a marathon, which energy system is the primary source of ATP?
A. ATP-PCr
B. Glycolytic
C. Oxidative
D. None
Rationale: Endurance exercise relies on oxidative metabolism of carbohydrates and fats.
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4. Which byproduct of anaerobic glycolysis contributes to muscle fatigue?
A. CO₂
B. Lactic acid
C. Creatine phosphate
D. Oxygen
Rationale: Accumulation of lactic acid reduces pH, impairing muscle contraction.
5. The ATP-PCr system can provide energy for approximately:
A. 5–10 seconds
B. 30–60 seconds
C. 2–3 minutes
D. Over 5 minutes
Rationale: Phosphagen stores supply energy for very short, explosive efforts.
6. Which macronutrient produces the most ATP per gram?
A. Carbohydrate
B. Protein
C. Fat
D. None
Rationale: Fat oxidation yields ~9 kcal/g, more than carbohydrates or protein (~4 kcal/g each).
7. Excess post-exercise oxygen consumption (EPOC) reflects:
A. Oxygen deficit during exercise
B. Recovery metabolism
C. Immediate ATP-PCr contribution
D. Depletion of muscle glycogen
Rationale: EPOC represents elevated oxygen consumption for restoring ATP, phosphocreatine,
and clearing lactate.
8. Which enzyme is the rate-limiting step of glycolysis?
A. Creatine kinase
B. Hexokinase
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C. Phosphofructokinase
D. Lactate dehydrogenase
Rationale: Phosphofructokinase regulates glycolysis based on ATP and ADP levels.
9. During high-intensity exercise, which substrate becomes the main ATP source after PCr
depletion?
A. Fatty acids
B. Glycogen
C. Protein
D. Lactate
Rationale: Glycolysis provides rapid ATP anaerobically after phosphagen stores are used.
10. Which factor most limits maximal aerobic capacity (VO₂max)?
A. Glycogen availability
B. Cardiac output
C. Muscle creatine phosphate
D. Blood glucose
Rationale: VO₂max is limited primarily by the cardiovascular system’s ability to deliver oxygen.
11–20: Muscle Fiber Types & Contraction
11. Type I muscle fibers are:
A. Fast-twitch, glycolytic
B. Slow-twitch, oxidative
C. Fast-twitch, oxidative-glycolytic
D. Anaerobic only
Rationale: Type I fibers have high endurance, rich in mitochondria, and rely on aerobic
metabolism.
12. Which fiber type fatigues most quickly?
A. Type I
B. Type IIa
2026 2027 GRADED A+