NSCA Certified Strength and Conditioning Specialist (CSCS)

Which muscle fiber type is most resistant to fatigue and relies primarily on oxidative metabolism?

• AType IIx
• BType IIa
• CType I
• DType IIb

According to the size principle of motor unit recruitment, which motor units are recruited first during a voluntary muscle contraction?

• ALarge motor units with high force output
• BSmall motor units with low recruitment thresholds
• CFast-twitch motor units with high contraction speeds
• DMotor units are recruited randomly based on need

During the sliding filament theory of muscle contraction, what role does calcium play?

• AIt binds to myosin heads to initiate the power stroke
• BIt binds to troponin, causing tropomyosin to shift and expose actin binding sites
• CIt directly provides energy for the cross-bridge cycle
• DIt breaks down ATP at the myosin head

Which of the following best describes Type IIa muscle fibers?

• ASlow-twitch, highly oxidative, low force production
• BFast-twitch, glycolytic only, highest force production
• CFast-twitch, both oxidative and glycolytic, moderate fatigue resistance
• DSlow-twitch, glycolytic only, moderate force production

What is the primary function of the Golgi tendon organ (GTO)?

• ADetect changes in muscle length and rate of length change
• BDetect tension in the muscle-tendon junction and inhibit muscle contraction
• CInitiate the stretch reflex to protect against overstretching
• DIncrease motor unit recruitment during maximal efforts

Which of the following structures stores and releases calcium ions during muscle contraction?

• ASarcolemma
• BT-tubules
• CSarcoplasmic reticulum
• DMitochondria

What is the difference between muscle hypertrophy and hyperplasia?

• AHypertrophy is an increase in fiber number; hyperplasia is an increase in fiber size
• BHypertrophy is an increase in fiber size; hyperplasia is an increase in fiber number
• CBoth refer to an increase in muscle fiber size through different mechanisms
• DHypertrophy occurs only in Type I fibers; hyperplasia occurs only in Type II fibers

Which type of muscle contraction occurs when the muscle produces force while lengthening?

• AConcentric
• BIsometric
• CEccentric
• DIsokinetic

The muscle spindle is primarily responsible for detecting:

• AChanges in muscle tension at the tendon
• BChanges in muscle length and the rate of length change
• CBlood flow changes within the muscle
• DMetabolic byproduct accumulation in the muscle

A strength and conditioning specialist observes that an athlete can produce more force during an eccentric contraction than a concentric contraction of the same muscle. This is best explained by:

• AGreater motor unit recruitment during eccentric actions
• BThe contribution of the series elastic component and titin during lengthening
• CHigher ATP consumption during eccentric actions
• DIncreased calcium release during eccentric actions

Which of the following best describes the all-or-none principle of motor unit recruitment?

• AAll muscle fibers in the body contract simultaneously or not at all
• BWhen a motor unit is activated, all muscle fibers in that motor unit contract maximally
• CA muscle either contracts at full force or does not contract
• DAll motor units in a muscle are recruited at the same threshold

An athlete performing heavy squats primarily relies on which mechanism to increase force production beyond initial motor unit recruitment?

• AAutogenic inhibition
• BReciprocal inhibition
• CRate coding (increased firing frequency)
• DMuscle spindle activation

Which of the following hormones has the greatest direct anabolic effect on skeletal muscle tissue?

• ACortisol
• BInsulin
• CTestosterone
• DEpinephrine

During a maximal isometric contraction, what happens to the length of the muscle fibers and the overall muscle-tendon unit?

• ABoth the muscle fibers and tendon remain the same length
• BMuscle fibers shorten slightly while the tendon stretches slightly, with no external move…
• CMuscle fibers lengthen while the tendon shortens
• DNeither the fibers nor the tendon change because no movement occurs