Glossary

R.I.C.E.—Rest, Ice, Compression, Elevation; the immediate treatment for most sudden athletic injuries.

radial artery—The artery in the wrist commonly used to take the pulse; The radial artery is located above the wrist, directly below the base of the thumb; generally considered the safest site for pulse monitoring.

random sample—A random sample is a procedure to select subjects for a study in which all individuals in a population being studied have an equal chance of being selected. using a random sample allows the results of the study to be generalized to the entire population. The term random also applies to assignments within controlled studies, or the division of subjects into groups. Random assignment ensures that all subjects have an equal chance of being in the experimental and control groups, and increases the probability that any unidentified variable will systematically occur in both groups with the same frequency. Randomization is crucial to control for variables that researchers may not be aware of or cannot adequately control, but which could affect the outcome of an experimental study.

random sampling—A method by which subjects are selected to participate in a study in which all individuals in a population have and equal chance of being chosen. This helps to ensure the generalizability of the study results.

randomization, or random assignment—A process of assigning subjects to experimental or control groups in which the subjects have an equal chance of being assigned to each group. Randomization is used to control for known, unknown and difficult-to-control-for variables.

range of motion (ROM)—The maximum motion allowed by muscles, joints, ligaments, tendons and the structure of the bones.

rating of perceived exertion (RPE)—Developed by Borg, this scale provides a standard means for evaluating a participant's perception of their physical exertion; the original scale was 6-20; the revised scale is 0-10; see also Borg’s scale (of perceived exertion).

RDA—The Recommended Dietary Allowance (RDA) is the dietary intake level that is sufficient to meet the nutrient requirements of nearly all individuals in a specific age and gender group.

RDI— The values listed on the food labels for nutrients reflect average allowances based on the RDA. These values are referred to as Reference Daily Intakes (RDIs).

reciprocal innervation—Reflex utilized with stretch reflex to inhibit activity of an opposing muscle group.

recombinant DNA (rDNA)—The DNA formed by combining segments of DNA from different organisms.

recruitment—Activation of motor units; the greater the resistance encountered, the greater will be the recruitment necessary to overcome its inertia.

reliability—Whether a test or instrument used to collect data, such as a questionnaire, gives the same results if repeated on the same person several times. A reliable test gives reproducible results.

repetition maximum (RM)—Maximal number of repetitions one can perform a given exercise at a given weight and intensity while using proper exercise form.

repetitions (reps)—Number of times a particular movement is performed.

research design—How a study is set up to collect information, or data. For valid results, the design must be appropriate to answer the question or hypothesis being studied.

residual volume—The air that stays in the lungs after breathing out as much as possible; the portion of the lungs which is not ventilated.

resistance—The amount of weight used in each set of an exercise.

respiratory or pulmonary—Referring to the lungs.

resting heart rate (RHR)—The heart rate upon awakening from sleep before sitting up, averaged over a three-day period; normally, the lower the heart rate at rest, the better aerobic condition the person is in.

resting metabolic rate (RMR)—Rate of body metabolism while conscious, but inactive.

retraction—Scapular adduction.

retrospective study—Research that relies on recall of past data, or on previously recorded information. Often this type of research is considered to have limitations, because the number of variables that cannot be controlled, and because memory is not infallible.

rheumatoid arthritis—Autoimmune disease that causes inflammation of connective tissues and joints.

ripped—Slang, meaning extremely visible muscularity resulting from both hypertrophy and subcutaneous fat removal, also referred to as shredded.

risk—A term encompassing a variety of measures of the probability of an outcome. It's usually used in reference to unfavorable outcomes such as illness or death. Be certain to distinguish between absolute and relative risk.

risk factor—A risk factor is anything statistically shown to have a relationship with the incidence of a disease, however it does not necessarily infer cause and effect.

risk factors—Used to help assess an individual’s predisposition to heart disease; includes heredity, blood pressure, diabetes, smoking, weight, cholesterol, exercise, emotional stress, age, sex, and body build.

RM—Acronym for "repetitions maximum"; Example: 5RM stands for the maximum amount of weight you can perform for five repetitions.

RNA—Also known as ribonucleic acid. RNA is a molecule similar to DNA that functions primarily to decode the instructions carried by genes for protein synthesis.

ROM—See range of motion.

rotator cuff—Four intrinsic muscles of the shoulder that help to rotate the arm and keep the humerus in the glenoid fossa during activity.

RPE—See rating of perceived exertion.