Below are concise definitions of some of the terms that are most frequently used in the discussion of nutritional supplements, exercise, and the human body.
acetaminophen
The generic name for the common nonprescription pain reliever and fever reducer (brand name of Tylenol).
acetylcholine
A chemical found in our bodies that carries information across the space between two nerve cells (neurons).
acidophilus
Bacteria that's typically found in yogurt that helps support a healthy intestinal tract (gut).
adenosine diphosphate (ADP)
An important chemical our cells use to produce energy—ADP forms when ATP (the source of cellular energy) breaks down to fuel muscle contractions. To recreate ATP and thus replenish our cells' energy stores, ADP combines with creatine phosphate.
adenosine triphosphate (ATP)
A compound that stores energy in muscles to fuel contractions. ATP breaks down into ADP to provide the energy for such muscle contractions. You can think of it as the actual fuel our muscles use to move.
adipose tissue
Fatty tissue that stores energy and insulates and cushions the body.
adrenal glands
Glands that reside above each kidney and secrete steroid hormones, including adrenaline and noradrenaline. The hormones produced by this gland are needed to control heart rate, blood pressure, food metabolism, and other essential activities in our bodies.
adrenaline
One of the hormones secreted by the adrenal glands that helps release sugar stored in the liver, increases blood supply to the muscles, and helps the muscles contract in response to stress or exercise. Often called the "fight or flight" hormone.
aerobic
Requiring oxygen. Aerobic exercise, for example, requires increased oxygen consumption. Opposite of anaerobic.
alpha-linolenic acid (ALA)
An essential fatty acid that comes from plants that is converted within the body to omega-3 fatty acids to be used as energy. Omega-3 fatty acids regulate a number of bodily functions, such as heart rate, blood pressure, and immune response. We need more ALA than any other type of essential fatty acid.
alveoli
Microscopic air sacs in the lungs where gases are exchanged.
Amanita mushroom
Amanita mushroom poisoning is often fatal, and silymarin has been shown in some studies to be 100 percent effective at preventing toxicity when taken before poisoning. And if given within 24 hours, it was shown to still prevent death and greatly reduce the amount of liver damage.
amino acid
A basic building block of protein that contains nitrogen. There are 22 amino acids, 8 of which cannot be produced within the body and are considered essential. Other amino acids appear to be conditionally essential because our bodies need more of them during stressful situations, including when recovering from intense exercise. The rest are considered nonessential.
anabolic
Relating to, characterized by, or promoting a state in which more muscle is being built up than torn down.
anabolism
A state in which more muscle is being built up than torn down.
anaerobic
Exercise employing short, vigorous bursts of activity with little additional oxygen requirements. Opposite of aerobic.
androgen
Any male sex hormone in our bodies.
androgenic
Hormones which produce masculine characteristics.
anorexia
An eating disorder involving loss of appetite for food, severe weight loss, and muscle wasting.
antibiotic
A chemical which has the ability to kill bacteria or other microorganisms or to inhibit their growth. They're often used in the treatment of infectious disease.
antibody
A protein produced by the immune system as the result of the introduction of an antigen, which is basically a threat to the immune system. Antibodies defend the body against substances that are potentially harmful, such as toxins and infections.
anticatabolic
Any substance that reduces muscle breakdown.
antioxidant
A substance that protects against cell damage by guarding cells from reactions with free radicals. Better known antioxidants include Vitamins A, C, and E and bioflavonoids.
antioxidants
Substances that protect against cell damage by guarding cells from reactions with free radicals. Better known antioxidants include Vitamins A, C, and E and bioflavonoids.
antiseptic
A substance that inhibits the growth and development of microorganisms, such as bacteria, viruses, or fungi, although it may not necessarily kill them.
arachidonic acid
An essential unsaturated fatty acid that's a precursor to regulatory substances in our bodies, such as leukotrienes, thromboxanes, and prostaglandins. It is found in animal fats such as liver and egg yolks and can also be created in our bodies from linoleic acid.
arteries
Vessels that supply oxygenated blood to tissues throughout our bodies.
arteriosclerosis
A disease characterized by the thickening, loss of elasticity, and calcification of arterial walls, resulting in decreased blood supply throughout the body, especially to the cerebrum part of the brain and the lower extremities. It often develops as people age or as a result of high blood pressure or diabetes.
ATP-citrate lyase
The enzyme responsible for the formation of acetyl-CoA, which is needed for the creation of fatty acids and cholesterol within our bodies. This enzyme is also responsible for converting excess sugars into fat.
autonomic nervous system
The part of the central nervous system that controls all involuntary functions, such as glandular activity, blood pressure, and heartbeat. Divided into the sympathetic and parasympathetic systems.
Ayurvedic
A holistic system of healing which evolved among the Brahmin sages of ancient India. Several aspects of this system of medicine distinguish it: 1) It focuses on establishing and maintaining balance of the life energies within us, rather than on individual symptoms. 2) It recommends different regimens for different types of people. 3) It seeks to heal the fragmentation and disorder of the mind-body complex and restore wholeness and harmony.
basal metabolic rate (BMR)
The rate at which the body burns calories or energy for internal functions, such as digestion, heartbeat, respiration, and the repair and maintenance of tissues.
bioavailability
The amount of a nutrient that enters the bloodstream and thus reaches the tissues and organs of the body.
biological value
A measure of protein quality, assessed by how well a given food or supplement supports nitrogen retention in humans.
blood pressure
The pressure of the blood in the main arteries, which rises and falls as the muscles of the body cope with varying demands, such as exercise, stress, and sleep. Two types of pressures are measured: systolic pressure, created by the contraction of the heart muscle, and diastolic pressure, when the heart is at rest between beats.
BPH
“Benign prostatic hyperplasia.” A condition in which the prostate is enlarged. Found in 50 to 60 percent of men between the ages of 40 and 59, BPH results in frequent urination during the night, difficulty urinating, interrupted flow or dribbling during urination, and a reduced sex drive. If an enlarged prostate is suspected, it is best to consult with your doctor and submit to a physical exam and a prostate specific antigen (PSA) test. BPH may lead to prostate cancer.
branched-chain amino acid
These three amino acids—valine, isoleucine, and leucine—account for one third of the protein in muscle tissue. This significant contribution makes them important for helping build muscle and increase energy in muscle cells. They are also converted to other amino acids when deficiencies arise.
buffer
A substance that minimizes changes in hydrogen-ion concentration (pH). Buffers such as sodium phosphate are used by athletes to help reduce lactic-acid accumulation.
bursa
Fluid-filled sac near or involving a joint or bony protrusion that help reduce friction between a tendon or bone or between bone and skin as we move.
bursitis
Bursitis is inflammation or irritation of the small fluid-filled sacs near or involving a joint or bony protrusion that helps reduce friction between a tendon or bone or between bone and skin as we move (bursa). Symptoms of bursitis and tendonitis are similar: pain and stiffness aggravated as we move. The most common cause of bursitis is injury or overuse during work or play.
calcification
The deposition of calcium salts in the body that occurs normally in teeth and bones but abnormally in injured muscles and narrowed arteries.
calorie
The measurement of heat or energy contained in food or expended during activity. One kilocalorie is the amount of heat required to raise the temperature of one kilogram of water one degree Celsius.
capillaries
The smallest, thin-walled blood vessels in the body.
carbohydrate
A sugar that provides the body’s main energy source. Includes monosaccharides (simple sugars such as fructose, galactose, and glucose), oligosaccharides (sugars containing 2 to 10 monosaccharides, such as lactose, maltose, and sucrose), and polysaccharides (complex sugars such as cellulose, glycogen, and starch). Carbohydrates contain four calories per gram. Glucose (blood sugar) is a carbohydrate used by every cell in the body as fuel.
carbohydrate loading
Increased consumption of carbohydrates prior to an endurance event to boost glycogen (blood sugar) stores.
carbon dioxide
A colorless, odorless gas present in small amounts in the atmosphere and formed as we breathe.
cardiovascular training
Conditioning that targets the cardiovascular system. Usually aerobic endurance training.
cartilage
A tough, stretchy connective tissue (softer than bone) that is part of the skeletal system, including the joints, and covers the ends of bones to form a low-friction, shock-absorbing surface for joints.
catabolism
The breakdown of body tissue, especially muscle.
catecholamine
Can act as hormones or chemical messengers and include adrenaline, noradrenaline, and dopamine.
cell volume
The cell becomes “super hydrated,” which research suggests may trigger greater protein synthesis and less muscle protein breakdown. This could lead to not only improved recovery but also enhanced muscle growth.
chelating agents
Soluble organic compounds that can fit certain metallic ions into their molecular structure. These are often used to increase the absorption of minerals within the body. For example, amino acids are very commonly used as chelating agents for iron and other poorly absorbed minerals.
chlorophyll
The green coloring of plants that absorbs sunlight.
cholesterol
A type of dietary fat that is often implicated in promoting heart disease and stroke and thus considered to be unhealthy. However, it is also needed for the production of many hormones in the body. Plus, it plays an important role in cell structure and functioning. There are two common forms of cholesterol—HDL (the "good" form) and LDL (the "bad" form).
choline
A natural substance found in food, often classified as a B vitamin, that's part of many other molecules, including acetylcholine and lecithin.
Choline Acetylase
An enzyme system that helps generate acetylcholine, an important neurotransmitter. (Acetylcholine is synthesized from choline and acetylCoA by the enzyme choline acetylase.)
cilia
Hair-like projections that protrude from cell membranes of the lungs and intestine to help propel substances out of the lungs or along the intestinal tract.
circuit training
A form of training involving moving quickly between many resistance exercise machines or stations. It provides both cardiovascular and resistance training.
coenzyme
A substance that works with an enzyme to promote the enzyme's activity. Many coenzymes have vitamins as part of their structures.
collagen
The tough, fibrous protein that is a major constituent of bone, cartilage, and connective tissues.
complete proteins
Proteins that contain all the essential amino acids in the right balance.
concentric contraction
The portion of an exercise when the muscle contracts or shortens.
connective tissue
The web-like tissue forming the supporting framework of the body and the internal organs, including bone, cartilage, and ligaments.
corpus cavernosum
The erectile tissue in the sex organs.
corticosteroids
Synthetic drugs that are used to replace natural hormones or to suppress the immune system and help prevent inflammation (such as cortisone).
cortisol
One of the primary catabolic hormones in the body. However, catabolism is not the only function of cortisol. It is typically secreted in response to physical trauma or prolonged stress. Its functions include controlling inflammation, increasing muscular catabolism and glycolysis, suppressing immune response, and maintaining normal vascular circulation and renal function, among others.
cortisone
A hormone produced by the adrenal gland and made synthetically that's important for the regulation of the metabolism of fats, carbohydrates, sodium, potassium, and proteins. It's also used to reduce inflammation.
creatine phosphate
An inorganic phosphate molecule that binds with ADP to form ATP. Supplementation with creatine monohydrate helps increase our muscles' creatine phosphate reserves.
creatinine
A protein made by muscles and shuttled into the blood. The amount produced is relatively stable per person. The level of creatinine is thus used to determine roughly how well the kidneys are functioning. Athletes, especially weight trainers, typically have elevated levels because they have greater amounts of muscle, not because of improper kidney functioning.
creatinine phospho-kinase
An enzyme found in the muscles. High levels in the blood indicate breakdown of muscle tissue.
cytokines
Substances secreted by immune-system cells to regulate immune functioning (such as lymphokins).
dehydration
Occurs when a person's body water content has decreased to a dangerously low level.
delayed-onset muscle soreness (DOMS)
A condition that occurs after exercise as a result of micro tears within muscles during the body-rebuilding phase. Lasts 24 to 72 hours.
dextrose
Another name for glucose.
diaphragm
The muscle wall between the chest and the abdomen that the body uses for breathing.
dietary supplement
Nutrients or combinations of nutrients that complete or add to our nutritional requirements.
dihydrotestosterone
Produced primarily in the androgen glands (e.g., the prostate), dihydrotestosterone is a metabolite of testosterone and is believed to be the hormonally active form of the masculine hormone testosterone.
dipeptide
Protein fragments made up of only two amino acids.
disc
A plate-like structure such as the cartilage cushion found between vertebrae.
dislocation
Displacement of a bone from its normal position in a joint.
diuretic
A compound that increases the rate of liquid excretion from cells, tissues, blood, and organs.
dopamine
A neurotransmitter (chemical brain messenger) and hormone that’s a precursor to adrenaline and noradrenaline.
eccentric contraction
Lengthening of muscles while under tension.
echocardiogram
A diagnostic test that employs ultrasound to determine structural and functional abnormalities of the heart.
edema
Swelling due to the abnormal accumulation of water.
efficacy
The ability of a supplement to produce a desired clinical effect.
elastin
A protein within our bodies that's similar to |collagen|. It's the main component of elastic fibers.
electrocardiogram (EKG)
A test measuring the electrical impulses corresponding to a heartbeat.
electrolyte
Charged particles throughout the body that are involved in numerous activities, such as regulating the distribution of water inside and outside cells in the body. Examples include the bulk minerals potassium, sodium, and chloride.
endocrine system
Ductless glands (including the pituitary, thyroid, thymus, and adrenal glands, as well as the pancreas, ovaries, and testes) that secrete hormones into the bloodstream to regulate body processes.
endorphin
A group of chemicals produced in the brain that reduce pain and improve mood.
endurance
Ability of a muscle to produce force continually over a period of time.
energy
The capacity to do work. The energy in food is chemical energy: it can be converted to mechanical, electrical, or heat energy. Energy is sometimes measured in "calories."
enzymatic
Of, relating to, or produced by an enzyme, which is the catalyst for all metabolic reactions.
enzyme
Complex protein compounds that speed biochemical reactions or act as helpers in thousands of chemical reactions within our bodies. Thousands of different enzymes are manufactured in the human body.
epinephrine
A hormone produced by the adrenal glands in response to stress, exercise, or fear that increases heart rate and opens airways to improve breathing. Also called adrenaline and known as the "fight or flight" hormone.
ergogenic
Anything that can enhance muscular work capacity—performance enhancing.
essential
Refers to nutrients the body must obtain from outside sources; i.e., food or supplementation.
essential fatty acids (EFA)
Fats our bodies can't make, so we must obtain them from food and/or supplementation. These fats (which include linoleic and linolenic acid) are very important to hormone production as well as cellular synthesis and integrity. Good sources of these fats are flaxseed oil and fish oils.
estrogen
A group of hormones produced mainly in the ovaries that are necessary for female sexual development and reproductive functioning.
exercise stress test
A test monitoring the heart during strenuous exercise, usually on a treadmill or exercise bicycle, to evaluate its responds to stress.
expectorants
A substance that helps the body get rid of or discharge mucus or phlegm from the respiratory tract.
fasciitis
Inflammation of the layer of connective tissue that covers, separates, and supports muscles.
fast-twitch muscles
Refers to muscle cells that fire quickly and are used in anaerobic activities such as sprinting, weight training, and power lifting.
fasting blood sugar
The level of glucose present in a blood sample drawn a minimum of eight hours after the last meal.
fat soluble
Substance capable of dissolving in the same organic solvents as fats and oils, which are stored in the liver and fatty tissues of the body, such as Vitamins A, D, E, and K.
fatty acids
Organic acids from which fats and oils are made. Required in the body for cell membrane function and integrity, healthy skin, cholesterol metabolism, and prostaglandin production. Fatty acids can be saturated (acetic, butyric, palmitic acids), monounsaturated (oleic acid), or polyunsaturated (linoleic, linolenic, arachidonic acids).
fibromyalgia
A mysterious condition of uncertain cause characterized by fatigue, pain, tenderness, and stiffness of muscles and joints.
flavonoids
Groups of compounds known for giving fruits and vegetables their colors (pigments), such as anthocyanins and flavones.
flexibility
Range of movement in a joint or group of joints.
flora
Plant life or bacteria in a specialized environment, such as our guts.
free radicals
Highly reactive molecules that possess unpaired electrons. Caused by pollution and exercise, they can cause cell damage and are believed to play a role in the aging process and cancer. Antioxidants protect against them.
free-form amino acids
Structurally unlinked, individual amino acids.
fructose
The main type of sugar found in fruit. It's sweeter than sucrose (table sugar) and has a low glycemic index. Eating fructose won't cause nearly as dramatic a release of insulin as glucose.
GABA receptor
GABA receptors are highly specialized receptors that contains five protein structures and are present on most nerve cells within the brain. There are three different kinds, one which binds with GABA, one which binds with benzodiazepines (e.g., Valium), and the third which binds with barbiturates and alcohol. Gamma-aminobutyric acid (GABA) is the main inhibitory or calming neurotransmitter in the central nervous system.
glucagon
A hormone produced by the pancreas that converts stored carbohydrates (glycogen) into glucose, the body’s energy source.
glucose
The simplest sugar molecule and the main sugar found in blood—it's the basic fuel our cells burn for energy.
glutathione
An abundant and essential antioxidant found within the cells that plays a huge role in the cell’s ability to fight free-radical damage.
glycemic index (GI)
A measure of the extent to which a food raises the blood sugar level as compared with white bread, which has a GI of 100. Examples include glucose at 138, brown rice at 81, and fructose at 31.
glycogen
The form of glucose stored primarily in the liver and muscles. It is converted back into glucose as needed to supply energy
glycolysis
The energy-yielding conversion of glucose to lactic acid.
gonads
Reproductive glands, such as an ovary or testis.
gram
A metric unit of weight measurement. Twenty-eight grams is equal to one ounce.
growth hormone (GH)
A hormone produced in the brain that promotes growth and aids in metabolism.
HDL cholesterol
Cholesterol packaged in high-density lipoproteins that removes cholesterol from the blood and is associated with a reduced risk of cardiac disease.
hemoglobin
The red protein pigment in blood cells that contains iron and delivers oxygen throughout the body.
homocysteine
An amino acid (a building block of protein) that's found in our blood and produced by our bodies that appears to increase the risk for heart disease, stroke, and vascular disease because it may irritate blood vessels, leading to blockages in arteries.
hormone-sensitive lipase
An enzyme that plays an important role in controlling the balance of energy by breaking down fats. It appears to be involved in the loss of insulin sensitivity that may lead to diabetes and obesity.
hormones
Produced by cells within our bodies, hormones circulate in the bodily fluids and produce specific effects by stimulating other cells.
hypertension
High blood pressure, indicated by a resting blood pressure reading higher than 140/90.
hypoglycemia
Abnormally low levels of glucose in the blood. Often, when people say they have this condition, they are describing how the body reacts—usually referring to anxiety, fatigue, headache, lack of concentration, the "shakes," sweaty palms, "starving," drowsiness, abdominal pain, and even depression. Many medical professionals refer to these symptoms as "reactive hypoglycemia."
hypoglycemic
Person with abnormally low levels of glucose in the blood, which can lead to feelings of anxiety, tension, and the "shakes."
hypothalamus
An endocrine gland in the brain that controls many aspects of metabolism, including regulating body temperature and appetite, through pituitary gland secretion.
hypothyroidism
Under-activity of the thyroid gland, causing tiredness, cramps, a slowed heart rate, and possibly weight gain.
hypoxia
A reduced level of oxygen in tissues.
immunoglobulins
A protein produced by the immune system as a result of the introduction of an antigen, which is basically a threat to the immune system. Antibodies defend the body against substances that are potentially harmful, such as toxins and infections.
inflammation
The body's reaction to tissue injury or infection characterized by reddening, pain, swelling, and warmth, due to increased blood flow in the traumatized area.
insulin
A muscle-building hormone secreted by the pancreas that aids the body in maintaining proper blood sugar levels and promoting glycogen storage. Insulin secretion speeds the movement of nutrients through the bloodstream and into muscle cells for growth.
ischemia
Reduced blood flow to a tissue or organ.
isoflavones
Compounds found in some foods that have weak estrogenic activity (a phytoestrogen). Isoflavones have been the subject of much research, especially for their possible cancer and heart-disease-preventive properties.
isolate
A substance that has been separated from a combined mixture.
isometric
Contracting a muscle against resistance without changing its length.
isotonic
Muscular action in which there is a change in length of muscle and weight, keeping tension constant. Lifting free weights is a classic isotonic exercise.
joint
The place where two bones meet. Most joints are composed of cartilage, joint space, fibrous capsule, synovium, and ligaments.
kilocalorie
A unit of energy; equal to a nutritional calorie.
Krebs cycle
A complex chemical pathway in the conversion of nutrients to energy.
kyphosis
Excessive curvature of the spine, which usually affects the top part of the spine and causes a hump.
lactic acid
A waste product of metabolism that accumulates in muscles during exercise that causes fatigue and soreness.
lactoferrin
A protein found naturally within milk and saliva, for two examples, as well as within white blood cells that has been shown in research to be a natural antibiotic, antioxidant, anti-fungal, antiviral, and immune booster.
lactoperoxidase
A component of cow's milk found in high concentrations in whey protein that appears to inhibit the activity of bacteria.
LDL cholesterol
Cholesterol packaged in low-density lipoproteins that is associated with an increase in the risk of heart disease. Low-density lipoproteins are the major carrier of cholesterol in the blood.
lean body mass
Everything in the body except fat.
lecithin
A phospholipid (that is, a substance that contains fatty acids and phosphorus) that is part of cell membranes and is also found in blood and egg yolks.
licorice
The dried root of the European plant Glycyrrhiza glabra or an extract of such used medicinally, in liquors, and in candies.
ligament
A tough, elastic band of fibrous tissue that connects bones and prevents excessive movement of joints.
lipoprotein lipase
An enzyme that breaks down fats.
lipotropic
A substance that promotes the use of fats.
lordosis
The inward curvature of the spine at the lower back, which is normal to a certain degree; abnormal as a result of excess weight and other health conditions.
luteinizing hormone
A hormone produced by the pituitary gland that stimulates development of tissues needed for reproduction and sexual functioning.
lymphatic
Of, relating to, or produced by lymph tissue.
lymphocytes
Constituting 20 to 30 percent of white blood cells, these colorless, slow-moving cells are created by lymph tissue (such as those in the thymus or bone marrow) and mediate immune functioning.
macronutrients
Nutrients we ingest in large quantities on a regular basis. These include proteins, carbohydrates, fats, and water. All of these nutrients are necessary for life.
mechanisms of action
How a nutrient or supplement works in the body.
metabolic rate
The speed at which the body uses energy. Resting metabolic rate is the rate of energy use at rest.
metabolism
The use of nutrients by the body and the processes by which substances come into the body and the rate they are used.
metabolite
Any substance that takes part in a chemical reaction in the body.
metabolites
Substances that take part in a chemical reaction in the body.
metabolizing
Either subject to or performing a chemical reaction within the body.
microgram (mcg)
A metric unit of weight measurement equal to one millionth of a gram. Micro means one millionth.
micronutrient
Any compound that is essential but only in small amounts (micro means small) for physical health, growth, and metabolism. Examples of micronutrients include vitamins and minerals.
microorganisms
An organism that 's extremely small (microscopic).
milligram (mg)
A metric unit of weight measurement equal to one thousandth of a gram. Milli is a prefix meaning one-thousandth.
mineral
Naturally occurring inorganic substances that are essential for human life and play a role in many vital metabolic processes. Calcium, magnesium, and zinc are just a few examples.
mitochondria
The energy factories of our cells. These various round or long cellular organelles are located outside the nucleus—the center of the cell—and produce cellular energy via cellular respiration. They have high concentrations of fats, proteins, and enzymes.
mitochondrion
(pl. mitochondria) The energy factories of our cells. These various round or long cellular organelles are located outside the nucleus—the center of the cell—and produce cellular energy via cellular respiration. They have high concentrations of fats, proteins, and enzymes.
mobilize
To be released so a substance can be used by the body.
monoamine oxidase (MAO)
An enzyme that removes an amino group (breaks down) to be combined with oxygen. It works in the nervous system to break down monoamine neurotransmitters.
monosaccharides
A simple carbohydrate made of one sugar molecule. An example is fructose.
mucous membranes
Any outer covering or lining which contains mucous-secreting glands, such as the lubricated lining of the mouth and nasal passages.
muscle tone
The natural tension in resting muscles.
muscles
Bundles of specialized cells that can contract and relax to move the body and organs.
myelin
The material that makes up the insulating layer surrounding nerve cells. It dramatically increases the speed of conduction.
myelin sheathe
The outside covering of a nerve cell to allow the transmission of nerve impulses.
nerve
A bundle of fibers that transmit electrical messages between the brain and areas of the body; these messages convey sensory or motor function information.
neuromuscular
Of or relating to both nerves and muscles jointly.
neurotransmitter
A chemical that transmits nerve impulses from one nerve cell to another or between a nerve cell and a muscle or organ. Some important neurotransmitters are serotonin, dopamine, norepinephrine, acetylcholine, and gamma-aminobutyric acid (GABA).
nitrogen balance
When a person's daily intake of nitrogen from proteins equals the daily excretion of nitrogen. A negative nitrogen balance occurs when the excretion of nitrogen exceeds the daily intake and is often seen when muscle is being lost. A positive nitrogen balance is often associated with muscle growth.
nitrogen retention
The body's ability to maintain positive nitrogen levels. A negative nitrogen balance occurs when the excretion of nitrogen exceeds the daily intake and is often seen when the muscle is being lost. A positive nitrogen balance is often associated with muscle growth.
nitrosamine
Various compounds characterized by an NNO grouping that are believed to be potent cancer-causing agents.
nonessential
Refers to a nutrient the body can produce when food sources are deficient in that nutrient. The body can survive without them.
nonessential amino acid
A basic building block of protein that contains nitrogen that the body can produce when food sources are deficient. The body can usually function normally even when we can't consume these nutrients.
norepinephrine
A hormone that's the neurotransmitter or brain messenger for most of the sympathetic nervous system.
nutrient
A substance the provides nourishment for the body.
one-rep max (1RM)
The most weight that can be lifted for one repetition with good form.
overload principle
Applying a greater load than normal to a muscle to increase its capability.
oxidation
A chemical reaction whereby oxygen reacts with another substance, thus changing the chemical makeup of the substance. In foods, this often results in deterioration or spoilage.
oxidative damage
The complications that arise from the havoc free radicals wreak in our bodies, which may lead to premature aging and disease states.
oxidative phosphorylation
Synthesis of ATP through various reactions whereby energy for the cell is obtained.
peripheral nervous system
The nerves that branch out from the brain and spinal cord to the rest of the body.
pernicious anemia
Also known as "megaloblastic anemia." A rare disease state that comes about when the body can't absorb enough Vitamin B12. The body becomes unable to produce enough red blood cells, and this results in fatigue, a fast pulse, sore mouth and tongue, and weight loss.
phytochemicals
A term used to refer to a broad spectrum of bioactive plant compounds that are typically used in herbal preparations and a variety of other nutrition supplements.
plyometric exercise
Exercise in which muscles are loaded suddenly and stretched, then quickly contracted to produce a movement.
polypeptide
Proteins formed by the union of three or more amino acids.
polyphenols
Compounds found in many plant foods that are known to have antioxidant activity, which may help our bodies fight the damage inflicted by free radicals.
polysaccharide
A carbohydrate made up of a combination of monosaccharide molecules, such as starch, dextrin, glycogen, and cellulose.
potassium
The third most abundant element in the human body. This essential mineral is involved in acid-base balance, the transfer of nutrients into and out of cells, insulin secretion, muscle relaxation, and various enzyme reactions.
precursor
A substance or component from which another substance or component is created.
preservative
Something added to a substance to prevent decay or spoilage.
progressive resistance
Method of training where weight is increased as muscles gain strength and endurance. The backbone of all weight training.
prostaglandins
Various animal fatty acids which perform hormone-like activity in the body, such as controlling blood pressure or muscle contractions.
protein
Highly complex nitrogen-containing compounds found in all animal and vegetable tissues. They are made up of amino acids and are essential for growth and repair in the body. A gram of protein contains four calories. Proteins are the building blocks of enzymes, muscle, and some hormones.
protein synthesis
The rate your muscles rebuild themselves after being broken down by intense training.
proteins
Highly complex nitrogen-containing compounds found in all animal and vegetable tissues. They are made up of amino acids and are essential for growth and repair in the body. A gram of protein contains four calories. Proteins are the building blocks of enzymes, muscle, and some hormones.
prothrombin
A protein produced in our livers with Vitamin K and found in the part of our blood called plasma that's converted into "thrombin," which is needed for our blood to clot.
pulmonary
Pertaining to the lungs.
pulse
Expansion of an artery following each contraction of the heart.
quadriceps
The large muscle on the front of the thigh that's divided into four parts.
radial artery
One of the main arteries of the arm, running down its full length into the hand. Arteries carry blood away from the heart.
range of motion (ROM)
The ability of a joint to go through all its normal movements. Range-of-motion exercises help increase or maintain flexibility and movement in muscles, tendons, ligaments, and joints.
red blood cell
A blood cell that contains hemoglobin (the red pigment that gives blood its color) and carries oxygen and carbon dioxide throughout the bloodstream. Also called erythrocytes.
repetition
One complete movement of an exercise.
rest interval
Pause between sets of an exercise, which allows muscles to recover partially before beginning the next set.
restless leg syndrome
A condition in which sufferers experience unpleasant sensations in the legs, especially the calves, thighs, and feet, especially at night. Often, patients complain of crawling, tingling, aching, stabbing, heaviness, or pins and needles sensations in one or both legs and even arms, usually when lying down or sitting. Involuntary leg movements often occur at night or sometimes during the day.
RPE
Rating of perceived exertion is a scale from one to ten used to assess exercise intensity. One is total relaxation while ten is maximum exercise intensity.
saturated fats
Fats that contain no open spots in the carbon structure of their molecules. Saturated fats have been shown to raise cholesterol levels in the body. These fats serve no biological purpose other than to supply calories.
serotonin
A neurotransmitter produced within the brain that aids in sleep and concentration as well has having a calming effect on mood.
serum
The watery part of a fluid that remains after it as clotted or coagulated.
set
A grouping of a fixed number of repetitions. For example, ten repetitions may comprise one set.
shock
A condition that may occur after a severe injury that results in a dangerous reduction of blood flow throughout the body tissues. If untreated, shock could lead to coma and death.
slow-twitch muscles
Muscle cells that contract slowly, are resistant to fatigue, and are used in endurance activities such as long-distance running, cycling, or swimming.
sodium-potassium pump
An example of the active transport of molecules across cell membranes. It maintains the electrochemical gradient across the cell membrane and is used in the ATP energy production system. Moving three sodium ions in the opposite direction of two potassium ions, the pump pushes positively charged ions out of the cell, causing the interior of the cell to become relatively negative.
solvent
A substance used to dissolve or be dissolved.
spasm
An involuntary muscle contraction—can sometimes be powerful and painful. Also called a cramp.
spot
Assistance provided to someone performing a resistance exercise.
static stretch
A stretch that is held in the stretched position for a given period of time.
steroids
A large group of naturally occurring and synthetic fat-soluble compounds with a wide diversity of physiological activity, such as hormones, some organic drugs (e.g. digitalis), bile acids, and cholesterol.
sterol
An inclusive term for all the compounds that are similar in makeup to cholesterol, such as the sex hormones, bile acids, Vitamin D, and the adrenal corticosteroid hormones.
sticking point
Most difficult part of an exercise.
strength training
Using resistance weight training to increase maximum muscle force.
stroke volume (SV)
The amount of blood pumped by the left ventricle during one heartbeat.
substrate
A substance that's acted upon, such as by an enzyme.
sucrose
Most commonly known as table sugar. When consumed, the body breaks sucrose down into fructose and glucose.
superoxide dismutase (SOD)
An enzyme within our bodies that contains metal and is used to reduce potentially harmful free radicals.
supine
Lying on the back.
synergistically
When supplements enhance or multiply each other's effects when used together (by "cooperating" in the body).
synovial fluid
A fluid released into movable joints by surrounding synovial membrane. Synovial fluid lubricates the joint and reduces friction.
tachycardia
A heart rate of over 100 beats per minute.
tannins
A soluble astringent substance that comes from plants that's used especially in tanning, dyeing, making ink, and in medicine.
target heart rate
The ideal intensity level at which your heart is being exercised but not overworked. Determined by finding your maximum heart rate and taking a percentage of it (60 to 85 percent, depending on fitness level).
tendinitis
Inflammation of a tendon, usually caused by injury, characterized by pain, tenderness, and sometimes limited movement in the attached muscle.
tendon
Strong connective-tissue cords that attach muscle to bone or muscle to muscle.
testosterone
A steroid hormone produced by the testes; it promotes the development of male sex characteristics and regulates male reproductive function. The primary and most potent androgen secreted by the testes.
thermogenic
The process of fat or calorie burning caused by increasing heat output.
thermogenics
Substances that may facilitate the process of fat or calorie burning caused by increasing heat output.
thymus or thymus gland
The glandular structure in the lymph system that is necessary for the body's immune functioning. It's found in the upper part of the front of the chest, just at the base of the neck. It tends to atrophy as we age.
thyroxin
A hormone produced by the thyroid gland that helps regulate energy production in the body. Iodine is an essential mineral that is an integral part of the thyroid hormones.
triglycerides
One of the three classes of fats, a triglyceride consists of three fatty acids and glycerol. Fat in the body is stored as triglycerides and blood levels are useful in diagnosing and treating diabetes, high blood pressure, and heart disease.
tripeptide
Consisting of three amino acids.
unsaturated fats
Fats that have been shown to help reduce cholesterol and triglyceride levels in the blood. EFA's and linoleic and linolenic acids are in this category of fats.
urea
One of the chief waste products of the body. When the body breaks down food, it uses what it needs and throws the rest away as waste. The kidneys flush the waste from the body in the form of urea in the urine.
vascular
Pertaining to the circulatory system.
vasoconstriction
Narrowing of blood vessels.
vasodilatation
Widening of blood vessels.
vein
One of the tubular branching vessels that carry blood from the capillaries toward the heart.
ventricle
One of the two lower chambers of the heart.
vestibular system
An organ of the inner ear containing several semicircular ducts at right angles to one another—helps keep the body balanced.
vitamin
Organic compounds that are vital to life, indispensable to bodily function, and needed in minute amounts.
VO2 max
The maximum amount of oxygen a person can use per minute of work, indicating cardiovascular efficiency.
warm up
Light gradual exercises performed to get the body ready for physical activity; normally a slower version of the activity to follow.
