Glossary

EAR— The Estimated Average Requirement (EAR) is the intake value that is estimated to meet the requirement defined by a specified indicator of adequacy in 50 percent of an age- and gender-specific group. At this level of intake, the remaining 50 percent of the specified group would not have its needs met. This figure is to be used as the basis for developing the RDA.

E. coli: O157:H7— The bacteria Escherichia coli: O157:H7 is a type of E. coli associated with foodborne illness. Healthy cattle and humans can carry the bacteria. It can be transferred from animal to animal and animal to human, and from animal to human on food. Transmission from person to person through close contact is a potential problem, especially among young children in daycare.

Environmental Protection Agency (EPA)— The EPA's mission is to protect human health and safeguard the natural environment - air, water and land - upon which life depends. Through regulation, EPA tries to ensure the human population and the environment are protected from environmental risks and exposures.

epidemiology— The study of distribution and determinants of diseases or other health outcomes in human populations. It seeks to expose potential associations between aspects of health (such as cancer, heart disease, etc.) and diet, lifestyle, habits or other factors within populations. Epidemiological studies may suggest relationships between two factors, but do not provide the basis for conclusions about cause and effect. Possible associations inferred from epidemiological research can turn out to be coincidental.

essentia— Nutrient that can not be manufactured by the body and must be consumed in food.

essential amino acid— Amino acids can not be manufactured in sufficient quantities in the body without being consumed in the diet. Essential amino acids include: tryptophan, valine, threonine, isoleucine, leucine, lysine, phenylalanine, and methionine.

essential fatty acid— Fatty acid that can not be generated by other fatty acids in the body. The essential fatty acids include linoleic, linolenic, and arachadonic acids.

etiology— The study of the causes of disease.

experimental group— The group of subjects in an experimental study which receives a treatment.

eccentric contraction (action)—A controlled lengthening of the muscle during its contraction; the resistance overcomes the muscular force and the muscle lengthens.

ectomorph—A thin body type; low fat content.

edema—Swelling due to abnormal accumulation of fluid in tissues or cavities.

ejection fraction—The percentage of the total volume of blood that is pumped out of the left ventricle during contraction of the heart.

elasticity—The ability of a tissue or other material to return to its original size or shape after stretching or elongation.

electrolytes—The minerals sodium, potassium and chlorine, which are present in the body as electrically charged particles called ions; Electrolytes are molecules that dissociate into cations or anions when fused or in solution, thus capable of conducting electricity; see ion.

Electron Transport System/Chain (ETS or ETC)—Process by which electrons are transferred between high energy intermediates to generate additional ATP in the presence of oxygen; occurs after the Kreb’s cycle in the mitochondria.

emergency medical services (EMS) system—A local system for obtaining emergency assistance from the police, fire department or ambulance service; In the United States, most cities have a 911 telephone number that will automatically set the EMS system in motion.

empathy—Understanding another person’s point of view in a manner that still allows objective reasoning.

emphysema—Chronic lung disease characterized by loss of air sacs resulting in a decreased ability to exchange gases; carbon dioxide levels are increased and oxygen levels are decreased, causing rapid breathing and dyspnea.

empty calories—Calories obtained from foods high in sugar and fat without significant nutritional value (vitamins and minerals).

endocrine—Pertaining to a gland that secretes directly into the bloodstream; the opposite of exocrine.

endocrine glands—Organs which secrete hormones into the blood or lymph systems to regulate or influence general chemical changes in the body or the activities of other organs; Major endocrine glands are the thyroid, adrenal, pituitary, parathyroid, pancreas, ovaries and testicles.

endomorph—A person whose body build is soft and round, with fat throughout the body; compare ectomorph and mesomorph.

endorphins—A natural chemical released by the body during exercise; Endorphins help relieve pain and leave the participant with a "natural high".

energy balance—The balance between energy taken in and energy used.

energy balance theory—The theory that body weight will stay the same when caloric intake equals caloric expenditure, and that a positive or negative energy balance will cause weight gain or weight loss.

enzymes—Proteins that speed specific chemical reactions.

epiphyseal cartilage—The place where growth occurs at the ends of the bones; If epiphyseal cartilage is damaged during growth, the bone may not reach its full potential; this is especially important when working with adolescents.

ergogenic aids—Substances thought to enhance energy availability or utilization to improve endurance or strength.

essential amino acids—Eight of the 23 different amino acids needed to make proteins in adults; called essential because they must be obtained from the diet, since they cannot be manufactured by the body.

essential fat—Fat that cannot be produced by the body and must be supplied by the diet; Linoleic acid, linolenic acid, and arachidonic acid are essential fats.

essential fatty acids—See essential fat.

essential nutrient—A nutrient that must be supplied by the diet because it cannot be produced in sufficient quantities by the body.

eumenorrheic—Having normal menstruation.

eversion—Turning outward.

exercise physiologist—A scientist who conducts controlled investigations of responses and adaptations to muscular activity utilizing human subjects or animals within a clinical, research, or academic setting; Exercise physiologists are degreed and certified in exercise physiology or a related field.

exercise physiology—The study of life processes as they relate to exercise.

exercise prescription—A physician’s recommendations or referral for exercise; the recommended volume of exercise including frequency, intensity, duration, and type of exercise.

exercise-induced asthma—Intermittent labored breathing precipitated by exertion during exercise; see also asthma.

exertional headaches—Pain triggered by a variety of exercise activities ranging from weightlifting to jogging, and including sexual intercourse.

extension—To straighten; movement of a body part away from the body; to increase the angle at a joint; Example, triceps extension.

external rotation—Rotary motion away from the midline of the body.