CSCS Periodization & Energy Systems 3 — Questions and Answers
Question 1: What is the primary fuel substrate used during low-intensity, prolonged aerobic exercise (>60 minutes)?
- Muscle glycogen exclusively
- Blood glucose exclusively
- Free fatty acids and intramuscular triglycerides (Correct answer)
- Creatine phosphate
Correct answer: Free fatty acids and intramuscular triglycerides
During prolonged low-intensity exercise, the oxidative system increasingly relies on free fatty acids and intramuscular triglycerides as glycogen is spared.
Question 2: In a traditional linear periodization model, which phase typically follows the hypertrophy phase?
- Peaking phase
- Active rest phase
- Basic strength phase (Correct answer)
- Power phase
Correct answer: Basic strength phase
Linear periodization progresses from hypertrophy → basic strength → strength/power → peaking, building on each preceding phase.
Question 3: Which enzyme is responsible for the rate-limiting step in glycolysis?
- Creatine kinase
- Phosphofructokinase (PFK) (Correct answer)
- Lactate dehydrogenase
- Citrate synthase
Correct answer: Phosphofructokinase (PFK)
Phosphofructokinase (PFK) catalyzes the key regulatory step in glycolysis and is highly sensitive to AMP, ADP, and pH changes.
Question 4: An athlete competing in multiple sports seasons per year would benefit most from which periodization approach?
- Linear periodization
- Block periodization
- Concurrent periodization
- Multi-peak periodization (Correct answer)
Correct answer: Multi-peak periodization
Multi-peak (or multiple-peak) periodization structures training to produce several performance peaks across a competitive year for athletes with multiple seasons.
Question 5: The Krebs cycle (citric acid cycle) takes place in which cellular compartment?
- Cytosol
- Nucleus
- Mitochondrial matrix (Correct answer)
- Sarcoplasmic reticulum
Correct answer: Mitochondrial matrix
The Krebs cycle occurs in the mitochondrial matrix, where acetyl-CoA is oxidized to produce NADH, FADH2, and CO2.
Question 6: Which periodization variable is most important to manipulate first when planning a new training phase?
- Training intensity
- Training volume (Correct answer)
- Exercise selection
- Rest interval length
Correct answer: Training volume
Volume is typically manipulated first when transitioning phases, as it sets the overall workload before intensity adjustments are made.
Question 7: A work-to-rest ratio of 1:12 to 1:20 is most appropriate for training which energy system?
- Oxidative system
- Fast glycolytic system
- Phosphagen (ATP-PCr) system (Correct answer)
- Combined glycolytic-oxidative system
Correct answer: Phosphagen (ATP-PCr) system
The phosphagen system requires long rest intervals (1:12–1:20) to allow full PCr resynthesis, enabling repeated maximal-effort bursts.
CSCS Periodization & Energy Systems 3
What is the primary fuel substrate used during low-intensity, prolonged aerobic exercise (>60 minutes)?