SCS Exercise Physiology & Biomechanics 5 — Questions and Answers
Question 1: Which concept describes the MINIMUM training stimulus required to produce a physiological adaptation?
- Principle of specificity
- Overload principle
- Threshold principle (Correct answer)
- Reversibility principle
Correct answer: Threshold principle
The threshold principle states that training intensity must exceed a minimum level to elicit adaptation; below this threshold, no meaningful physiological change occurs.
Question 2: During a bilateral squat, peak knee joint moment is GREATEST at which point in the descent?
- At approximately 90° of knee flexion (Correct answer)
- At the initiation of descent
- At the top of the movement
- At maximum ankle dorsiflexion
Correct answer: At approximately 90° of knee flexion
Knee extensor moment peaks near 90° of knee flexion where the moment arm of body weight relative to the knee joint is longest.
Question 3: The Fick equation calculates VO2 as the product of cardiac output and which other variable?
- Hemoglobin concentration
- Arteriovenous oxygen difference (a-vO2 diff) (Correct answer)
- Tidal volume
- Respiratory quotient
Correct answer: Arteriovenous oxygen difference (a-vO2 diff)
The Fick equation: VO2 = Q × (CaO2 − CvO2), where the a-vO2 difference represents oxygen extraction by the working tissues.
Question 4: Which training method BEST improves the rate of force development (RFD) in athletes?
- High-volume hypertrophy training (3×12–15)
- Slow-tempo eccentric training
- Ballistic and plyometric training (Correct answer)
- Static stretching protocols
Correct answer: Ballistic and plyometric training
Ballistic movements and plyometrics train the nervous system to recruit motor units rapidly, directly improving RFD which is critical for sport performance.
Question 5: Increased muscle temperature during warm-up enhances performance PRIMARILY by:
- Increasing muscle glycogen stores
- Improving actin-myosin cross-bridge cycling speed and enzyme activity (Correct answer)
- Reducing neuromuscular activation
- Decreasing muscle blood flow
Correct answer: Improving actin-myosin cross-bridge cycling speed and enzyme activity
Elevated muscle temperature speeds enzyme kinetics, cross-bridge detachment rates, and nerve conduction velocity, improving mechanical efficiency and power output.
Question 6: An athlete's center of mass (COM) is located LOWEST relative to the base of support when in which position?
- Standing at full height with arms overhead
- Deep squat position (Correct answer)
- Single-leg stance on toes
- Standing broad jump take-off position
Correct answer: Deep squat position
In a deep squat, the COM drops significantly below the hips, providing the greatest static stability due to a lower COM and wide base of support.
Question 7: Which adaptation is MOST responsible for reduced submaximal exercise heart rate after 8–12 weeks of aerobic training?
- Decreased sympathetic nervous system activity and increased parasympathetic tone (Correct answer)
- Increased maximal heart rate
- Reduced hemoglobin concentration
- Decreased tidal volume at rest
Correct answer: Decreased sympathetic nervous system activity and increased parasympathetic tone
Aerobic training enhances vagal (parasympathetic) tone and reduces sympathetic drive, resulting in lower resting and submaximal heart rates.
SCS Exercise Physiology & Biomechanics 5
Which concept describes the MINIMUM training stimulus required to produce a physiological adaptation?