MCTs Exercise Science 5 — Questions and Answers
Question 1: What is the typical respiratory exchange ratio (RER) when fat is the predominant fuel?
- About 0.70 (Correct answer)
- About 0.85
- About 1.00
- About 1.20
Correct answer: About 0.70
Fat oxidation produces an RER near 0.70, while carbohydrate produces about 1.00.
Question 2: Which term describes the smallest functional unit of muscle contraction?
- Myofibril
- Sarcomere (Correct answer)
- Fascicle
- Motor neuron
Correct answer: Sarcomere
The sarcomere, between two Z-lines, is the basic contractile unit.
Question 3: Which ion released from the sarcoplasmic reticulum initiates muscle contraction by binding to troponin?
- Sodium
- Potassium
- Calcium (Correct answer)
- Magnesium
Correct answer: Calcium
Calcium binds troponin, shifting tropomyosin to expose actin binding sites.
Question 4: According to Henneman's size principle, which motor units are recruited first?
- Largest, fast-twitch units
- Random units
- Units in the dominant limb
- Smallest, low-threshold units (Correct answer)
Correct answer: Smallest, low-threshold units
Motor units are recruited from smallest to largest as force demand increases.
Question 5: A periodization model that varies intensity and volume within the same week is called what?
- Linear periodization
- Undulating periodization (Correct answer)
- Block periodization
- Reverse linear periodization
Correct answer: Undulating periodization
Undulating (nonlinear) periodization changes training variables frequently, often daily or weekly.
Question 6: Which measure is the gold-standard indicator of cardiorespiratory fitness?
- Resting heart rate
- Body mass index
- VO2 max (Correct answer)
- Blood lactate at rest
Correct answer: VO2 max
VO2 max reflects the maximal rate of oxygen uptake and use during exercise.
Question 7: Performing an exercise against resistance through the full range of motion at a constant velocity describes which type of contraction?
- Isokinetic (Correct answer)
- Isotonic
- Isometric
- Plyometric
Correct answer: Isokinetic
Isokinetic contractions occur at a constant speed, usually using specialized equipment.
MCTs Exercise Science 5
What is the typical respiratory exchange ratio (RER) when fat is the predominant fuel?