Key Words
Activities of daily living (ADLs): activities normally performed for hygiene, bathing, household chores, walking, shopping and similar activities
Atrophy: a reduction in muscle size (muscle wasting) due to inactivity or immobilization
Base of support: the areas of contact between the feet and their supporting surface and the area between the feet
Chronic disease: any disease state that persists over an extended period of time
Concentric: a muscular contraction in which the muscle develops tension and shortens when stimulated
Eccentric: a muscular contraction in which the muscle lengthens against a resistance when it is stimulated
Essential amino acids: eight to 10 of the 23 different amino acids needed to make proteins. Called essential because the body cannot manufacture them; they must be obtained from the diet
Estrogen: in addition to its role as a female sex hormone, decreased estrogen levels, especially after menopause, are linked to decreased muscle size and force in women, contributing muscle weakness and leading to decreased strength and frailty in post-menopausal women
Exercise set: the number of cycles of repetitions completed
Extension: the act of straightening or extending a joint, usually applied to the muscular movement of a limb
Flexion: the act of moving a joint so that the two bones forming it are brought closer together
Growth hormone: a hormone that stimulates growth; secreted by the pituitary gland
Impact: the action of one object coming forcibly in contact with another; affects movements progressing from one foot remaining in contact with the floor during exercise increasing to plyometric activity
Insulin: a hormone released from the pancreas that allows cells to take up glucose
Insulin-like growth factor: mainly secreted by the liver as a result of stimulation by growth hormone, important in the regulation of normal physiology
Intensity: the measurable amount of force or physical power that the body uses when performing an activity
Isometric: a type of muscular contraction in which the muscle is stimulated to generate tension but little or no joint movement occurs
Joint stability: the ability to maintain or control joint movement or position
Lever length: the distance between the axis and point of resistance applied
Mobility: the degree to which an articulation is allowed to move before being restricted by the surrounding tissues
Motor neurons: responsible for sending signals from the brain to the muscles to initiate movement
Motor unit: consists of the motor nerve and all the muscle fibers it stimulates. Groups of motor units work together to coordinate contractions of a single muscle
Muscle contraction: the activation of tension-generating sites within muscle fibers
Muscular endurance: the ability of a muscle or muscle group to exert force against a resistance over a sustained period of time
Muscle force-velocity relationship: the force generated by a muscle is a function of its velocity. Related to muscular power
Muscle power: the ability to exert maximal force in as short a time as possible, as in accelerating, jumping and throwing. Power is proportional to the speed at which maximal force can be applied
Muscular strength: the maximum force applied against a load
Overload: providing a greater than normal stress, or load, on the body to stimulate further strength development
Overexertion: pushing oneself past the point of what a person decides is appropriate for themselves or exceeding the limits of one’s ability
Perceived exertion: how hard a person feels they are working
Periodization: systematic planning of physical training with the goal of improving performance; cycling various aspects of a training program such as increasing or decreasing repetitions, exercise sets, intensity or other variations to continually make progressive strength changes
Plyometric: high intensity movement such as jumping, involving high-force loading of body weight during the landing phase of the movement in short intervals of time, with the goal of increasing power (speed + strength)
Progression: the systematic process of applying overload
Protein: a compound composed of a combination of 20 amino acids that is the major structural component of all body tissue
Protein synthesis: the process by which amino acids are arranged into proteins, which is responsible for cell structure and function
Range of motion: the number of degrees that an articulation will allow one of its segments to move
Rate of perceived exertion (RPE): a scale, originally developed by Swedish psychologist Gunnar Borg, that provides a standard means for evaluating a participant’s perception of exercise effort. The original scale ranged from 6 to 20; SilverSneakers uses a revised category ratio scale from 1 to 10
Reaction time: a measure of how quickly one can respond to a particular stimulus
Regression: variations or modifications to decrease the intensity or complexity of an exercise or movement
Repetitions: the number of times a specific exercise is performed
Resistance: an increased force or load applied to a movement or muscular contraction
Rhythm: a strong, regular, repeated pattern of movement or sound
Sarcopenia: an age-related decline in muscle mass or lean-body tissue
Stability: characteristic of the body’s joints or posture that represents resistance to change of position; the ability to maintain or control joint movement or position
Testosterone: in addition to its role as a male sex hormone, it also plays a role in fat distribution, red cell production and maintenance of muscle strength and mass
Velocity: the speed of something in a given direction