Chapter 4: Muscular Strength and Endurance Flashcards
A single muscle cell, usually classified according to strength, speed of contraction, and energy source.
Muscle fiber
A tough band of fibrous tissue that connects a muscle to a bone or other body part and transmits the force exerted by the muscle.
Tendon
Protein structures that make up muscle fibers (‘myo’ means muscle).
Myofibrals
A cell structure containing DNA and genes that direct the production of proteins; pl., nuclei.
Nucleus
Cells that provide additional cell nuclei in skeletal muscle, which enhances muscle protein synthesis and cell repair.
Satellite Cells
An increase in the size of muscle fibers, usually stimulated by muscular overload, as occurs during strength training.
Hypertrophy
An increase in the number of muscle fibers.
Hyperplasia
A decrease in the size of muscle fibers, usually attributable to inactivity.
Atrophy
Red muscle fibers that are fatigue resistant but have a slow contraction speed and a lower capacity for tension; usually recruited for endurance activities.
Slow-twitch muscle fibers
White muscle fibers that contract rapidly and forcefully but fatigue quickly; usually recruited for actions requiring strength, power, or speed.
Fast-twitch muscle fibers
The ability to exert force rapidly.
Power
A long, slender part of the nerve cell that conducts the nerve impulse away from the nerve cell body.
Axon
A fatty material covering the nerve cell that insulates the axon. Practicing a motor skill lays down more myelin on the axon, which speeds neural conduction and improves skills such as hitting a tennis ball or baseball or skiing down a hill.
Myelin
The principal male hormone, responsible for the development of secondary sex characteristics and important in increasing muscle size.
Testosterone
Activating muscle contractions explosively, regardless of weight used. Also called compensatory acceleration training.
Purposeful Strength training
The maximum resistance that can be moved a specified number of times. One RM is the maximum weight that can be lifted one time; 5 RM is the maximum weight that can be lifted five times.
Repetition Maximum (RM)
The number of times an exercise is performed during one set.
Repetitions
Exercise causing a muscle contraction without a change in the muscle’s length or a joint’s angle.
Isometric (Static) exercise
Exercise causing a muscle contraction and a change in the muscle’s length.
Isotonic (Dynamic) exercise
A dynamic contraction in which the muscle gets shorter as it contracts; also called a miometric contraction.
Concentric Muscle Contraction
A dynamic contraction in which the muscle lengthens as it contracts..
Eccentric Muscle Contraction
A type of dynamic exercise that uses a constant load throughout a joint’s full range of motion.
Constant resistance exercise
A type of dynamic exercise that uses a changing load, providing a maximum load at the strongest point in the affected joint’s range of motion.
Variable Resistance exercise
Loading the muscle while it is lengthening; sometimes called negatives.
Eccentric Loading
Rapid stretching of a muscle group that is undergoing eccentric stress (that is, the muscle is exerting force while it lengthens), followed by a rapid concentric contraction.
Plyometrics
Moving a load as rapidly as possible.
Speed Loading
A type of dynamic exercise that provides variable resistance to a movement, so that the movement occurs at a constant speed no matter how much effort is exerted. (biking)
Isokinetic exercise
Exercising with restricted blood flow to working muscles. Also called Kaatsu training.
Blood Flow restriction training
Destruction of muscle tissue resulting in the release of enzymes and electrolytes from the cell contents, which can cause kidney damage and even death. This usually occurs during traumatic injuries such as automobile accidents. Overzealous training programs can also cause “rhabdo.”
rhabdomyolysis
Substances consumed to improve athletic performance.
ergogenic aids
A change in the normal pattern of the heartbeat.
Arrhythmia
Elevated blood glucose (blood sugar) levels caused by metabolic problems.
Glucose intolerance
A central nervous system stimulant found in coffee, tea, chocolate, and energy drinks; it increases energy level and alertness.
Caffeine
