Exercise Science Principles Flashcards

An athlete performs a set of high-load (85% 1RM) back squats for 5 repetitions. Which muscle fiber type is MOST likely the primary contributor to this effort, and what is its key characteristic?

Answer: Type IIx; highest force production and low fatigue resistance

High-load, low-repetition exercises like a 5-rep max back squat primarily recruit Type IIx muscle fibers. These fibers, also known as fast-glycolytic fibers, are capable of producing the greatest amount of force among all fiber types, but they are highly fatigable due to their reliance on anaerobic metabolism. Type I fibers are for endurance, and Type IIa fibers are recruited for activities that require high power output for a longer duration than a 5-rep max set.

During a heavy deadlift, an athlete suddenly relaxes and drops the weight. This relaxation is primarily caused by the activation of which sensory receptor, and what is its function?

Answer: Golgi Tendon Organ; to cause muscle relaxation when high tension is detected

The Golgi Tendon Organ (GTO) is a proprioceptive sensory receptor located at the junction of the muscle and tendon. It is sensitive to changes in muscle tension. When an excessively high level of tension is detected, as in a maximal or near-maximal lift, the GTO is stimulated and causes a reflex inhibition (relaxation) of the contracting muscle. This protective mechanism, called autogenic inhibition, prevents the muscle and tendon from being damaged. Muscle spindles, in contrast, respond to a rapid stretch by causing a muscle to contract.

A strength and conditioning coach designs a hypertrophy-focused program for a bodybuilder. Which of the following training variable combinations would elicit the MOST significant acute increase in serum growth hormone and testosterone levels?

Answer: High volume, moderate-to-high intensity (e.g., 4 sets of 10 reps at 75% 1RM), short rest periods (60-90 seconds)

Research consistently shows that resistance training protocols characterized by high volume, moderate-to-high intensity, and short rest periods produce the greatest acute elevations in anabolic hormones like testosterone and growth hormone. This type of training, stressing a large muscle mass, creates significant metabolic stress, which is a key trigger for this hormonal response. The other options involve either too little intensity, too little volume, or rest periods that are too long to maximize this acute endocrine response.

A novice athlete exhibits significant knee valgus (knees collapsing inward) during the concentric phase of a heavy back squat. From a biomechanical perspective, which of the following is the MOST likely contributor to this movement fault?

Answer: A strategy to increase the contribution of the hip adductors and shift load to the hips.

During a heavy squat, especially near the sticking point, knee valgus can occur as a strategy to overcome the difficult portion of the lift. This inward movement of the knees allows for greater involvement of the powerful hip adductor muscles in hip extension. It also shifts the center of pressure and can move the hips back, increasing the hip extension moment arm. While sometimes attributed to weak glutes, research has shown this is not always the case, and it is often a compensatory strategy to lift maximal loads.

Which of the following represents a chronic cardiovascular adaptation specifically associated with long-term, high-intensity anaerobic training like resistance training?

Answer: Increased left ventricular wall thickness (concentric hypertrophy)

High-intensity anaerobic training, such as heavy resistance exercise, imposes a pressure overload on the heart. To counteract the high blood pressure experienced during lifts, the heart adapts by increasing the thickness of the left ventricular wall. This adaptation is known as concentric hypertrophy. In contrast, aerobic endurance training typically leads to an increase in the chamber size (eccentric hypertrophy). While anaerobic training can lead to some improvements, significant increases in VO2 max are characteristic of aerobic training. Capillary density typically increases, not decreases, to aid recovery.

According to the principle of Specificity, which training modality would be MOST effective for improving a basketball player's vertical jump height?

Answer: Plyometric exercises and Olympic-style lifts to increase the rate of force development.

The principle of Specificity states that training adaptations are specific to the stimulus applied. A vertical jump is a power-based movement that requires a high rate of force development (RFD). Therefore, training should mimic the velocity and force characteristics of the desired action. Plyometric exercises (like box jumps) and Olympic-style lifts (like the power clean) are performed explosively and directly train the neuromuscular system to produce force quickly, thus having the greatest transfer to improving vertical jump height.