NCAA CPL Human Performance flashcards

32 cards. Read the term and the definition here. The deck at the top of this page is optional.

Sarcomere

The functional contractile unit of skeletal muscle, bounded by two Z-discs; actin and myosin filaments slide past one another during contraction to shorten the sarcomere.

Sliding filament theory

Contraction model in which myosin heads bind actin and perform a power stroke, pulling thin filaments toward the sarcomere center; requires ATP and calcium binding to troponin.

Motor unit

One alpha motor neuron and all the muscle fibers it innervates; smaller innervation ratios allow finer control, while larger ratios generate more force per recruitment.

Length-tension relationship

Active muscle tension is greatest near optimal filament overlap, roughly 2.0-2.2 micrometers sarcomere length, and declines when the muscle is over-shortened or over-stretched.

Type I muscle fibers

Slow-twitch oxidative fibers with high mitochondrial and capillary density and low fatigability; suited to posture and prolonged submaximal endurance activity rather than rapid force production.

Eccentric contraction

Muscle action in which the muscle lengthens while producing tension, generating higher force than isometric or concentric actions at a given velocity but with greater soreness risk.

Third-class lever

Lever where the effort lies between fulcrum and load, as in a biceps curl; favors speed and range of motion over mechanical advantage, and is the most common human lever.

ATP-PCr system

Immediate energy system using creatine phosphate and creatine kinase to regenerate ATP without oxygen; dominates the first 5-10 seconds of maximal effort.

Anaerobic glycolysis

Breakdown of glucose or glycogen to pyruvate and lactate without oxygen, yielding about 2-3 ATP; dominant energy source for high-intensity efforts lasting roughly 10 seconds to 2 minutes.

Lactate threshold

Exercise intensity at which blood lactate rises above baseline; the second threshold approximates maximal lactate steady state and strongly predicts endurance performance.

VO2max

Maximal rate of oxygen uptake, equal to cardiac output multiplied by arteriovenous oxygen difference; a key marker of aerobic capacity and endurance performance potential.

Heart rate reserve method

Karvonen formula: target heart rate equals (maximal heart rate minus resting heart rate) multiplied by intensity percentage, then plus resting heart rate.

EPOC

Excess post-exercise oxygen consumption; elevated oxygen uptake after exercise that restores phosphagen stores, clears lactate and hormones, and returns the body to resting state.

Crossover point

Intensity around 60 percent of VO2max where carbohydrate contribution begins to exceed fat oxidation as fiber recruitment and catecholamines rise.

Torque

Rotational effect of a force, calculated as force multiplied by the perpendicular moment arm; joint torque depends on muscle force and its changing internal moment arm.

Impulse-momentum relationship

Impulse, the product of force and time, equals the change in momentum; lengthening contact time reduces peak forces in landing or increases implement speed in throwing.

Angular momentum conservation

In flight, total angular momentum (moment of inertia times angular velocity) stays constant; reducing moment of inertia by tucking increases spin rate, and extending slows it.

Tangential velocity

Linear speed of a point moving on a circular path, equal to angular velocity multiplied by radius; longer limbs or implements increase endpoint speed.

Base of support

Area beneath the body bounded by contact points with the ground; stability increases with a larger base and a center of mass projected well inside it.

Fitts and Posner stages

Three stages of motor learning: cognitive, marked by large errors and verbal cues; associative, with refinement; and autonomous, where the skill becomes automatic.

Contextual interference

Practice effect in which random or interleaved practice depresses immediate performance but improves retention and transfer compared with blocked practice.

Knowledge of results

Augmented feedback describing the outcome of a movement, such as distance or accuracy; distinct from knowledge of performance, which describes movement quality.

Fitts' law

Movement time increases linearly with the index of difficulty, defined as the base-2 logarithm of twice the target distance divided by target width.

Closed motor skill

Skill performed in a stable, predictable environment where the performer controls timing, such as a free throw or a golf drive.

Carbohydrate loading

Protocol of 8-12 grams of carbohydrate per kilogram per day for 24-48 hours before endurance events above roughly 90 minutes to maximize muscle glycogen stores.

Low energy availability

Condition where energy intake minus exercise expenditure leaves insufficient energy for body functions, below about 30 kcal/kg fat-free mass per day, impairing hormones and bone.

Creatine monohydrate

Supplement taken at about 3-5 grams daily, or loaded at 20 grams daily for 5-7 days, that raises phosphocreatine stores and benefits short high-intensity efforts.

Sweat rate calculation

Body mass lost during exercise plus fluid consumed, divided by exercise duration in hours; used to individualize fluid replacement and limit losses above 2 percent body mass.

Epley formula

Method estimating one-repetition maximum as weight lifted multiplied by one plus repetitions divided by 30; valid mainly for sets below about 10-12 repetitions.

Progressive overload

Systematic increase in training load, volume, frequency, or density over time to drive adaptation; the core principle underlying strength and endurance program progression.

Exertional heat stroke

Medical emergency with core temperature typically above 40 C and central nervous system dysfunction; requires immediate cold-water immersion cooling rather than transport first.

Self-determination theory

Motivation framework stating that satisfying competence, autonomy, and relatedness needs produces autonomous motivation, which predicts better long-term exercise adherence than controlled motivation.