Schwinn Bike Energy Systems 3 — Questions and Answers
Question 1: How does interval training in an indoor cycling class improve the lactate threshold over time?
- It increases the size of ATP-PCr stores
- It trains muscles to clear and use lactate more efficiently (Correct answer)
- It eliminates the need for anaerobic metabolism
- It reduces the body's reliance on oxygen
Correct answer: It trains muscles to clear and use lactate more efficiently
Repeated interval training increases mitochondrial density and lactate clearance enzymes, raising the lactate threshold.
Question 2: What is the approximate duration of maximal effort that the phosphagen system alone can sustain?
- 30–60 seconds
- 1–2 minutes
- 5–10 seconds (Correct answer)
- 3–5 minutes
Correct answer: 5–10 seconds
The phosphagen system can sustain all-out effort for only about 5–10 seconds before phosphocreatine stores are depleted.
Question 3: During an indoor cycling hill climb segment lasting 4–5 minutes at near-maximal effort, which two energy systems are primarily working together?
- Phosphagen and oxidative
- Glycolytic and oxidative (Correct answer)
- Phosphagen and glycolytic
- Oxidative and beta-oxidation
Correct answer: Glycolytic and oxidative
Efforts lasting 1–5 minutes at high intensity rely heavily on both fast glycolysis and the aerobic oxidative system simultaneously.
Question 4: What role does oxygen play in the aerobic energy system during indoor cycling?
- It is used to break down phosphocreatine
- It acts as the final electron acceptor in the electron transport chain (Correct answer)
- It directly converts glucose to ATP
- It neutralizes lactic acid in the blood
Correct answer: It acts as the final electron acceptor in the electron transport chain
In aerobic metabolism, oxygen accepts electrons at the end of the electron transport chain, enabling maximum ATP production.
Question 5: Which energy system is primarily responsible for ATP production during the recovery period between hard intervals in a cycling class?
- Phosphagen system
- Anaerobic glycolysis
- Aerobic oxidative system (Correct answer)
- Creatine kinase reaction
Correct answer: Aerobic oxidative system
During recovery, the aerobic system replenishes ATP and phosphocreatine stores while clearing accumulated metabolites.
Question 6: A rider's respiratory exchange ratio (RER) is measured at 0.75 during a steady ride. What does this indicate about their fuel use?
- Primarily burning carbohydrates
- Primarily burning fats (Correct answer)
- Equal mix of fat and carbohydrate
- Burning protein exclusively
Correct answer: Primarily burning fats
An RER of 0.70 indicates pure fat oxidation; 0.75 reflects predominantly fat being used as fuel.
Question 7: Which adaptation results from consistent aerobic indoor cycling training that directly improves energy system efficiency?
- Decreased cardiac output
- Increased mitochondrial density in muscle cells (Correct answer)
- Reduced capillary density
- Lower stroke volume at rest
Correct answer: Increased mitochondrial density in muscle cells
Aerobic training increases the number and size of mitochondria in muscle cells, enhancing oxidative energy production capacity.
Schwinn Bike Energy Systems 3
How does interval training in an indoor cycling class improve the lactate threshold over time?