Exercise Science Fundamentals Flashcards

During a box jump, which phase of the stretch-shortening cycle is the brief transition between landing (eccentric loading) and takeoff (concentric force)?

Answer: Amortization phase

The amortization phase is the dynamic stabilization period between the eccentric and concentric phases, and shorter amortization produces more power.

A client training for a marathon will rely most on which muscle fiber type, characterized by high mitochondrial and capillary density?

Answer: Type I

Type I (slow-twitch) fibers are small, fatigue-resistant, and rich in mitochondria and capillaries, making them ideal for endurance.

According to Henneman's size principle, how are motor units recruited as force demands increase?

Answer: Smallest to largest

The size principle states that smaller, low-threshold motor units are recruited first, followed by larger, high-threshold units as force needs rise.

Which principle explains why bone density increases in response to the mechanical loads placed on it during resistance training?

Answer: Wolff's law

Wolff's law states that bone adapts and remodels according to the loads placed upon it.

The elbow joint during a biceps curl is an example of which class of lever, the most common type in the human body?

Answer: Third-class lever

In a third-class lever the effort (biceps insertion) lies between the fulcrum (elbow) and the resistance (weight in the hand).

Which energy system is the primary supplier of ATP during an all-out effort lasting about 45-60 seconds, such as a 400-meter sprint?

Answer: Anaerobic glycolysis

Anaerobic glycolysis predominates for high-intensity efforts lasting roughly 30 seconds to 2 minutes.

A client with chronically tight hip flexors shows reduced neural drive to the gluteus maximus. What is this phenomenon called?

Answer: Altered reciprocal inhibition

Altered reciprocal inhibition occurs when a tight agonist decreases neural drive to its functional antagonist.