Glossary

lactate—The anaerobic product of glysolysis in animals. Formed under conditions that do not favor aerobic breakdown of pyruvate, the end product of glycolysis.

lactic acid (lactate)—A bi-product of anaerobic energy production known to cause localized muscle fatigue when it accumulates during short-term, high intensity exercise; It is associated with fatigue.

lactic acid system—See anaerobic glycolysis.

lacto-ovo vegetarians—Vegetarians who will eat dairy or eggs.

lactose—A sugar naturally occurring in milk, also known as "milk sugar," that is the least sweet of all natural sugars and used in baby formulas and candies.

lactose intolerance—Lactose intolerance is an inherited inability to properly digest dairy products, due to a deficiency in the amount of the enzyme, lactase in the small intestine. This enzyme is necessary for the hydrolysis of lactose (a disaccharide) into its constituent monosaccharides, glucose and galactose. Symptoms of lactose intolerance, including abdominal cramps, flatulence and frothy diarrhea, can increase with age.

lateral—Anatomical term meaning away from the midline of the body, toward the side.

lats—Slang referring to the latissimus dorsi, the large muscles of the back that are the prime movers for adduction, extension and hyperextension of the shoulder joints.

law of acceleration—Force (F) acting on a body in a given direction is equal to the body's mass (m) multiplied by the body's acceleration (a) in that direction; F = ma, or a = F/m.

law of inertia—The tendency of all objects and matter to remain at rest, or, if moving, to continue moving in the same straight line unless acted on by an outside force; proportional to body mass.

lean body mass—See fat-free mass.

lever—A rigid bar that rotates around a fixed support (fulcrum) in response to an applied force; A lever transmits and modifies force or motion. The bones act as levers in the body.

liability—Legal responsibility.

ligament—A band of non-elastic tough connective tissue connecting the articular ends of the bones; frequently the stabilizing element of a joint.

lipids—Fats or fat-like substances.

lipolysis—The splitting of a fat molecule.

lipoprotein—Vehicle that transports fat throughout the body; made up of protein, fat and cholesterol.

locomotion—Movement from one place to another.

longevity—Length of life.

lordosis—A normal curvature of the lower back; this can also refer to an excessive inward curvature (hyperlordosis) or lack of curvature in the lumbar area (hypolordosis); Hyperlordosis predisposes the participant to a higher risk of injury.

low-calorie sweetener—Low-calorie sweeteners are non-nutritive sweeteners, also referred to as intense sweeteners. Low-calorie sweeteners can replace nutritive sweeteners in most foods at a caloric savings of approximately 16 calories per teaspoon. Thus, caloric reduction may be achieved when low-calorie sweetened foods and beverages are substituted for their full-calorie counterparts. Examples of low-calorie sweeteners in use in the U.S. food supply are saccharin, aspartame, and acesulfame K.

low-density lipoproteins (LDLs)—Plasma complex of lipids and proteins that contains relatively more cholesterol and triglycerides and less protein; High LDL levels are associated with an increased risk of coronary heart disease.

lumbar curve—Curve which is formed from the 5 vertebrae found in the lower back; this curve is slightly concave; see lordosis.

lycopene—Lycopene is a carotenoid related to the better known beta-carotene. Lycopene gives tomatoes and some other fruits and vegetables their distinctive red color. Nutritionally, it functions as an antioxidant. Research shows lycopene is best absorbed by the body when consumed as tomatoes that have been heat-processed using a small amount of oil. This includes products such as tomato sauce and tomato paste. Also, see functional foods.

lysis—The splitting of a molecule. (Ex. Hydrolysis, glycogenolyis, lipolysis, etc.)