Glossary of Fitness and Health Terms
A to Z list of useful health and fitness terms.
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Acetyl-CoA - The metabolic intermediate that
is produced when carbohydrate or fat undergoes
beta-oxidation. It is then available to be used for
energy production via the Krebs cycle or through the
formation of ketone bodies.
Acromegaly - Pathological enlargement of the
bones of the hands, feet and face resulting from chronic
over activity of the pituitary gland. Only results from
disease of the pituitary or exogenous growth hormone
Adenosine Triphosphate (ATP) - The final step
of the Krebs Cycle. This molecule collects the potential
energy from nutrients that is released during
beta-oxidation and carries it to the cells of the body
to be used for energy.
Adipose Tissue - Bodily connective tissue that
contains stored cellular fat.
Adrenal Glands - Either of two small endocrine
glands, one located above each kidney, consisting of the
cortex, which secretes several different hormones, and
the medulla, which secretes epinephrine.
Adrenal Medulla - The center of the adrenal
gland that secretes the hormone epinephrine.
Adrenaline - Another name for epinephrine.
Aerobic - Living or occurring only in the
presence of oxygen.
Aerobics - Conditioning of the cardiopulmonary
system by means of vigorous exercise that seeks to
increase efficiency of oxygen intake, build the
cardiovascular system and increase metabolic activity.
Agility - A skill-related component of
physical fitness that relates to the ability to rapidly
change the position of the entire body in space with
speed and accuracy.
Amino Acids - The essential components of
protein. These are the building blocks of the all the
cells in the body. There are about 20 different amino
acids that occur in the human body.
Ammonia - The byproduct of amino acid usage by
the muscles for energy. Very toxic, it is converted to
urea by aspartates in the urea cycle, which can then be
disposed of in urine.
Anabolic - The process by which simple
substances are synthesized into the complex tissue of
Anaerobic - Living or occurring without the
presence of oxygen.
Androgens - A steroid hormone that develops
and maintains masculine characteristics. They also are
potent stimulators of linear growth in children whose
epiphyses has not closed yet. They also promote muscle
Anemia - A deficiency in the oxygen-carrying
material of the blood, measured in volume concentrations
of hemoglobin, red blood cell volume and red blood cell
Aspartates - Chemical compound that is used by
the body to detoxify waste products created by amino
Autocrine Hormones - Hormones that exert their
effect only on the cells that produce them. Balance A
skill-related component of physical fitness that relates
to the maintenance of equilibrium while stationary or
Basal Metabolic Rate - The body’s energy
expenditure while at rest. This represents the energy
requirements for maintaining life, consisting mostly of
maintenance of temperature, heart rate, breathing nerve
transmission, electrochemical gradients across cell
membranes and the energy cost of protein turnover
required to maintain cells.
Beta-Oxidation - Fatty acid catabolism in
which two carbon fragments are removed from the fatty
acid chain, producing acetyl-CoA which can then travel
through the Krebs cycle or be synthesized into ketones
and used as energy.
Bile - An alkaline liquid secreted by the
liver and stored in the gall bladder which is sent to
the intestines to be used to break down fat.
Body Composition - A health-related component
of physical fitness that relates to the relative amounts
of muscle, fat, bone and other vital parts of the body.
Body Fat - The amount of adipose tissue
carried on the body.
Bone Integrity (Bone Strength) - A
non-performance component of fitness related to bone
Branched Chain Amino Acids (BCAAs) - The amino
acids leucine, isoleucine and valine, these are
important for synthesis of other amino acids and can be
used directly by the muscle for energy.
Calcium - A very important mineral used in the
formation and maintenance of teeth and bones as well as
other metabolic processes in the body.
Calorie - A measure of energy from food.
(3,500 kilocalories of food energy = 1 pound of
bodyweight). Also the amount of heat required to raise
the temperature of 1 gram of water 1° C (1000 calories =
1 kilocalorie). An interesting fact: When we see
"Calories" on a food label it is actually measuring
Carbohydrate - Any of a group of chemical
compounds, including sugars, starches and cellulose,
containing carbon, hydrogen and oxygen.
Carbon - A natural element occurring in many
inorganic and all organic compounds.
Cardiorespiratory Endurance - The ability of
the body's circulatory and respiratory systems to supply
fuel and oxygen during sustained physical activity.
Cardiorespiratory Fitness - Also called
aerobic endurance or aerobic fitness.
Cardiovascular Density - The size and number
or blood vessels and capillaries capable of transporting
oxygen to cells and removing waste from cells.
Cardiovascular Fitness - A health-related
component of physical fitness that relates to ability of
the circulatory and respiratory systems to supply oxygen
during sustained physical activity.
Carnitine Shuttle - A metabolic process in
which long chain triglycerides are actively transported
across the membrane of the mitochondria to be burned for
Catabolic - Metabolic change of complex
molecules into simple molecules. Cellulose - A
carbohydrate, is the main constituent of all plant
tissues and fiber. Cannot by digested by the human body.
Cholesterol - A crystalline substance, the
most common animal sterol. Is a universal tissue
constituent occurring most notably in bile, gallstones,
the brain, blood cells, plasma, egg yolk and seeds.
There are two types: high density lipoprotein and low
density lipoprotein. High density lipoprotein is
important for many physiological processes. Low density
lipoprotein has been show to build up in arteries
causing blockages which can lead to heart disease.
Chondrocytes - Layers of cartilage which are
the framework for bone formation.
Chylomicrons - A microscopic fat molecule in
the blood that is formed during the digestion of fat.
Coordination - A skill-related component of
physical fitness that relates to the ability to use the
senses, such as sight and hearing, together with body
parts in performing motor tasks smoothly and accurately.
Cortisol - One of the glucocorticoids, this
hormone, derived from the adrenal cortex, acts to
stimulate optimal levels of metabolic enzymes used
during growth. Low cortisol prevents growth because
enzyme levels are too low, while excess cortisol causes
Diabetes - A disease caused by a severe
deficiency of insulin production by the pancreas. Mild
cases can be regulated through diet while others require
Digestion - The primarily enzymatic process of
breaking down the food ingested into simple, assimilable
Duodenum - The beginning portion of the small
intestine, extending from the lower end of the stomach
to the jejunum.
Electrolytes - A substance that dissociates
into ions in solution when fused, thereby becoming an
electrical conductor. The body uses many different
electrolytes for physiological processes.
Endochondrial Ossification - The process in
which proliferating cartilage is replaced by bone.
Endocrine Hormones - A classification of
hormones, meaning that they are released into the
bloodstream and are carried throughout the body. Also
know as telecrine hormones.
Endocrine System - Consisting of several
organs of the body, including the pituitary, thyroid,
adrenal and parathyroid glands, the pancreas, testes or
ovaries and kidneys, this systems transports information
to different parts of the body through chemical
messages. These messages are called hormones.
Energy - The work a physical system is capable
of doing in changing from its actual state to a
specified reference state.
Energy Balance -The bodily process of using as
much energy as it is provided through nutrition. This
includes energy expenditure through basal metabolism,
physical activity and thermogenesis.
Enzymes - Any of numerous proteins or
conjugated proteins produced by living organisms and
functioning as biochemical catalysts in living
Epinephrine - An adrenal hormone from the
adrenal medulla that stimulates autonomic nerve action.
Has been shown to have a great impact on fat loss. When
activated, it is carried throughout the body, preparing
muscles for action and mobilizing fat from adipose
stores for energy. Also known as adrenaline.
Epiphyseal Plate - The ends of the bones that
continue to grow throughout childhood and adolescence.
They usually close during puberty, at which point bone
growth is stopped.
Erythrocytes - The blood cell that contains
hemoglobin and is responsible for the color of blood.
Essential Amino Acids - Eight amino acids
which are not capable of being produced by the body and
must be obtained through dietary protein.
Essential Fatty Acids - A group of fatty acids
which are physiologically important to good health.
Estrogen - One of several steroid hormones produced
chiefly by the ovary and responsible for the regulation
of certain female reproductive functions and the
development and maintenance of female secondary sex
Exercise - The physical activity that is
planned or structured. It involves repetitive bodily
movement done to improve or maintain one or more of the
components of physical fitness--cardiorespiratory
endurance (aerobic fitness), muscular strength, muscular
endurance, flexibility, and body composition.
Fascial Stretching - A specialized form of
stretching developed by
Parrillo in which the fascia tissue which envelopes
the muscle is stretched, allowing for more muscle
Fat - Any of various soft solid or semisolid
organic compounds comprising fatty acids and associated
phosphatides, sterols, alcohols, hydrocarbons, ketones
and related compounds. A mixture of such compounds
widely occurring in organic tissue, especially in the
subcutaneous connective tissue of animals and in the
seeds, nuts and fruits of plants.
Fatty Acids - Any of a large group of acids
containing hydrogen and carbon and is obtainable from
animals and plants. These acids combine to form fat.
Fiber - One of the elongated, thick-walled
cells giving strength and support to plant tissue. An
important part of the diet for regulation of digestion
and elimination of digestive waste.
Flexibility - A health-related component of
physical fitness that relates to the range of motion
available at a joint.
Food - Material, usually plant or animal,
containing or consisting of essential nutrients, as
carbohydrates, protein, fat, vitamins, or minerals,
taken in and assimilated by an organism to maintain
growth and life.
Food Efficiency - The calories consumed of a
certain amount of food divided by weight gain. Foods
with a high food efficiency tend to add to weight gain
while foods with a low food efficiency are more prone to
be used as energy rather than stored as body weight.
Fructose - A sweet sugar that is found in many
fruits and honey. Is prone to being stored as body fat.
Gall Bladder - A small, pear-shaped sac
located under the right lobe of the liver, in which bile
secreted by the liver is stored.
Gastrointestinal Tract - Of or relating to the
stomach and intestines and process by which food travels
through these organs.
Glucagon - A hormone secreted by the pancreas
which increases blood sugar by activating the metabolism
of fat from adipose tissue and amino acids from muscle.
This hormone has the opposite reaction of insulin.
Glucocorticoids - A group of hormones
responsible for stimulating or regulating optimal levels
of enzymes whose activities are then regulated by other
Gluconeogenesis - Process in which amino acids
are changed into glucose in the liver which can then be
used as energy.
Glucose - The combination of simple sugars
that is formed by the digestion of food and is released
into the bloodstream to be used for energy, converted
into muscle glycogen or stored as body fat. Glucose is
the trigger mechanism for the release of insulin from
Glycogen - The primary storage carbohydrate in
animals. Glycogen can be stored in the muscles for
immediate energy needs or can be stored in the liver.
Glycogen Supercompensation - A process of
depleting glycogen stores in the muscle and liver by
carbohydrate restriction, and then replenishing them
past the storage limit they had before.
Glycogen Synthase - The enzyme responsible for
Glycolysis - The anaerobic production of ATP
from carbohydrate. This is the primary energy source for
intense exercise for short periods of duration.
Golgi Tendon Organ - A group of sensory
receptors in the muscle that fire when the tendon is
stretched too far and shuts down the muscle.
Golgi Tendon Reflex - The shutting down of the
muscle by the golgi tendon organ during exercise.
Growth Hormone - Produced by the pituitary
gland, this anabolic hormone is the most responsible for
growth during childhood. It has profound effects on
development of the skeleton and muscles. Even after
physical stature is attained, growth hormone can still
have a great effect on muscle growth.
Growth Hormone Releasing Hormone (GHRH) - A
hormone released by the hypothalamus which triggers
growth hormone release.
Health - The state of being associated with
freedom from disease and illness that also includes a
positive component (wellness) that is associated with a
quality of life and positive well-being. Health-related
physical fitness consists of those components of
physical fitness that have a relationship with good
health. The components are commonly defined as body
composition, cardiovascular fitness, flexibility,
muscular endurance, and strength.
Hemoglobin - The oxygen-bearing,
iron-containing protein in blood cells.
Hormone Receptors - Special molecules on cells
that interpret the signal being sent by hormones.
Hormone Sensitive Lipase - An enzyme produced
by epinephrine that breaks down fat triglycerides into
free fatty acids and glycerol. The free fatty acids can
then leave the adipose tissue into the bloodstream and
be used for energy by the muscles.
Household physical activity -Activity that
includes (but is not limited to) activities such as
sweeping floors, scrubbing, washing windows, and raking
Hypercaloric - Increasing caloric consumption.
Hyperphagia - Overeating.
Hypocaloric - Restricting caloric consumption,
Hypoglycemia - An abnormally low level of
glucose in the blood. Can be caused by carbohydrate
restriction or overly high insulin levels.
Hypophysectomy - Removal of the pituitary
gland. Hypothalamus - The part of the brain that lies
below the thalamus and functions to regulate autonomic
activities, like body temperature and weight. It
connects the pituitary to the brain and is the link
between the endocrine system and the nervous system.
Inactivity - Not engaging in any regular
pattern of physical activity beyond daily functioning.
Insulin - Powerful anabolic hormone released
by the islands of Langerhans in the pancreas. Functions
to regulate carbohydrate metabolism by controlling blood
glucose levels. Also has a hand in storage of fat and in
the entry of amino acids into muscles.
Insulin-Like Growth Factor (IGF) - An
important peptide for the regulation of growth hormone.
Produced by the liver, it has an insulin-like effect on
Iron - An important metallic element that is
used by the cardiovascular system to bind iron to
hemoglobin and myoglobin. It also is required by enzymes
when oxygen is consumed in the cells.
Ischemic Rigor - When the muscle is depleted
of ATP and it locks in a contracted state and cannot
Jejunum - The section of the small intestine
between the duodenum and the ileum.
Ketogenesis - The process of two acetyl-CoA
molecules joining to create a ketone molecule.
Ketones - An organic compound made in the
liver when carbohydrate or fat is metabolized and
creates an abundant amount of acetyl-CoA. This
overwhelms the Krebs cycle and the extra acetyl-CoA is
synthesized into ketones. These ketones are then
released into the bloodstream and taken up by the
muscles and used as fuel.
Kidneys - Either of a pair of structures in
the dorsal region of the abdominal cavity, functioning
to maintain proper water balance, regulate acid-base
concentration, and excrete metabolic wastes as urine.
Kilocalorie -The amount of heat required to
raise the temperature of 1 kg of water 1° C. Kilocalorie
is the ordinary calorie discussed in food or exercise
energy-expenditure tables and food labels.
Krebs Cycle - A series of enzymatic reactions
in aerobic organisms involving oxidative metabolism of
acetyl units, especially during the process of
respiration, to provide the main source of cellular
energy in the form of ATP.
Lactic Acid - Produced by anaerobic metabolism
of carbohydrates in the muscle. It is what gives the
muscles a burning sensation during and after strenuous
work. Most lactic acid makes its way out of the muscle
and into the bloodstream where it can be transported to
the liver to be converted back into glucose for fuel
Lactose - A simple sugar found in greatest
quantities in milk products. Lipid - One of numerous
fats and fat-like materials that are generally insoluble
in water but soluble in common organic solvents. They
are related to the fatty acid esters and together with
carbohydrates and proteins constitute the principal
structural material of living cells.
Lipolysis - The breakdown of fat for energy.
Lipoprotein Lipase - A fat-storing enzyme
triggered by low caloric intake.
Liver - A large compound, tubular gland that
secretes bile and acts in formation of blood and in
metabolism of carbohydrates, fats, proteins minerals and
Lymphatic System - A network of vessels
throughout the body for transporting large particles.
This is the pathway used by fat to get from the
intestines to the bloodstream and finally to adipose
Malonyl-CoA - A substance produced during
carbohydrate metabolism that inhibits the action of the
carnitine shuttle in moving fat into the mitochondria.
Maltodextrin - Starch produced from grain
containing the sugars maltose and dextrin.
Mass - The physical volume or bulk of a solid
body. Different from weight.
Metabolic Fitness - The state of metabolic
systems and variables predictive of the risk for
diabetes and cardiovascular disease which can be
favorably altered by increased physical activity or
regular endurance exercise without the requirement of a
training-related increase in VO2max.
Metabolic Rate - The measurement of the body’s
ability to utilize food for energy.
Metabolism - The complex of chemical and
physical processes involved in the maintenance of life.
Minerals - A naturally occurring, homogeneous
inorganic substance with a specific chemical
composition. These play specific roles in the body.
Mitochondria - A microscopic body occurring in
the cells of nearly all living organisms and containing
enzymes responsible for the conversion of food for
Morphological Fitness - A non-performance
component of fitness related to body composition factors
such as body circumferences, body fat content, and
regional body fat distribution.
Motor Skills - Non-fitness abilities that
improve with practice (learning) and relate to one's
ability to perform specific sports and other motor
Muscle - A tissue made up of fibers that can
contract and relax to effect body movement. It is the
most metabolically active tissue in the body.
Muscular Endurance - A health-related
component of physical fitness that relates to the
muscle's ability to continue to perform without fatigue.
Myofibrils - Muscle fibers.
Myoglobin - The form of hemoglobin found in
Negatives - The eccentric or lowering part of
Nervous System - A coordinating system that
regulate internal body functions and responses to
external stimuli; in vertebrates it consists of the
brain, spinal cord, nerves, ganglia and parts of
receptors and effector organs. This system transmits
messages throughout the body through electrical signals.
Nitrogen Balance - The difference between the
amount of nitrogen taken into and lost by the body. Used
to determine if protein intake is adequate.
Nutrients - The basic substances that are
necessary for life derived from food.
Nutrition - The process of nourishing or being
nourished. Especially by which a living organism
assimilates food and uses it for growth, energy and
Obesity - A condition of having an
overabundance of adipose tissue on the body. Usually is
determined by having 30% body fat or more.
Oxidation - Combination of a substance with
oxygen, usually generating another substance and heat.
Oxidative Phosphorylation - A vital process of
intracellular respiration occurring within the
mitochondria of the cell, responsible for most ATP
Oxygen - A colorless gas comprising 21% of the
atmosphere by volume and essential to most combustion
and combustive processes.
Pancreas - A long, soft, irregularly shaped
gland lying behind the stomach that secretes digestive
enzymes and produces insulin and glucagon.
Paracrine Hormones - Hormones that are
released into the interstitial space between tissues and
exert their effect only on nearby cells.
Parathyroid Glands - Any of four small
kidney-shaped glands that lie in pairs near the lateral
lobes of the thyroid gland and secrete a hormone
necessary for calcium and potassium metabolism.
Passive Diffusion - The act of a substance
moving into a cell without resistance from that cell.
Peptides - A natural or synthetic compound containing
two or more amino acids linked by the carboxyl group of
one amino acid and the amino acid group of another.
Physical Activity - Any bodily movement
produced by skeletal muscles that result in an
expenditure of energy.
Physical Fitness - A set of attributes a
person has in regards to a person's ability to perform
physical activities that require aerobic fitness,
endurance, strength, or flexibility and is determined by
a combination of regular activity and genetically
Physiological Fitness - Includes
non-performance components of physical fitness that
relate to biological systems that are influenced by
one's level of habitual physical activity.
Pituitary Gland - A small, oval, endocrine
gland attached to the base of the vertebrate brain
(hypothalamus) and whose secretions control the other
endocrine glands and influence growth, metabolism and
Portal Vein - A vein that conducts blood from
the digestive organs, spleen, pancreas and gall bladder
to the liver.
Potassium - A metallic element found in or
converted to a wide variety of salts. Used by the body
in several different ways, but primarily for water
Potential Energy - The energy of a particle or
system of particles derived from position rather than
motion. It is the amount of energy a substance has
available for work but has not used yet.
Power - A skill-related component of physical
fitness that relates to the ability to the rate at which
one can perform work.
Protein - Any of a group of complex
nitrogenous organic compounds that have amino acids as
their basic structural units and that are found in all
living matter and are required for the growth and repair
Quality of Life - A term that connotes an
overall sense of well being.
Reaction Time - A skill-related component of
physical fitness that relates to the time elapsed
between stimulation and the beginning of the reaction to
Recommended Daily Allowance (RDA) - A group of
standards put forth by the National Research Council
indicating the minimum amount of nutrients that should
be eaten daily.
Respiratory Quotient - The ratio of carbon
dioxide produced to oxygen consumed. Used to determine
the type of nutrient being used for energy.
Serum - The clear, yellowish fluid that
comprises the liquid part of whole blood.
Skeletal Muscle - A collection of striated
muscle fibers connected at either or both extremities
with the bony framework of the body.
Sodium - A soft, metallic element. Used by the
body for many purposes, mainly as a regulator of water.
Somatomedin Hypothesis - A theory that growth
hormone on its own does not promote growth but that some
other intermediate substance, known as somatomedin C,
stimulated by growth hormone is the substance that
Somatomedin-C (IGF-1) - Known also as
insulin-like growth factor (IGF), this substance
produced primarily by the liver has been shown to
promote growth in the absence of growth hormone. It also
has insulin-like effects on glucose.
Somatotropes - The cells in the pituitary
gland which produces growth hormone.
Speed - A skill-related component of physical
fitness that relates to the ability to perform a
movement within a short period of time.
Strength - A health-related component of
physical fitness that relates to the ability of the
muscle to exert force.
Sugar - Any of a class of water-soluble,
crystalline carbohydrates. Sugars can be either simple
(only one) or starches (two or more sugars combined).
Testes - The male reproductive gland, the
source of spermatozoa and of the androgens, particularly
testosterone. The testes is usually paired in an
external scrotum in most animals.
Testosterone - A male sex hormone produced in
the testes and controlling secondary sex
Thermic Effect of Food (TEF) - Also known as
the thermogenic effect, it is the measurement a food’s
energy plus its tendency to be burned.
Thermogenesis - The process of food being
burned and releasing energy as heat.
Thoracic Duct - The main duct of the lymphatic
system, ascending along the spinal cord and discharging
into the venous system.
Thyroid Gland - A two-lobed endocrine gland
found in all vertebrates, located in front of and on
either side of the trachea, and producing the hormone
Thyroid Hormone - Present in two forms, T3 and
T4 and produced in the thyroid. Most of the circulating
hormone is T4 which is then converted to T3 inside the
target cell. This hormone has little growth factor by
itself, but helps to regulate, synthesize and promote
the action of growth hormone.
Thyroidectomy - The surgical removal of the
Triglyceride - An ester of three fatty acids
and a glycerol. Triglycerides can be classed as long
chain (meaning they contain fatty acids that have 16-22
carbon atoms) which are predominant in conventional
dietary fat, and medium chain (fatty acids with 6-14
carbon atoms) which are found in some foods but are not
predominant. LCTs and MCTs are metabolized differently
by the body.
Urea - A compound found in urine and other
bodily fluids, synthesized from ammonia and carbon
Vitamins - Any of various relatively complex
organic substances found in plant and animal tissue and
required in small quantities for controlling metabolic
VO2max - 75% of the maximal aerobic capacity.
This measure is used to determine the intensity of
Weight - The measure of the heaviness of an
object as gravitational force is exerted on that object.
Different from mass.
Wellness - A state of being describing a state
of positive health in the individual and comprising
biological and psychological well-being as exemplified
by quality of life and a sense of well-being.
Source: www.cdc.gov, www.fitness.gov,
Frank Moran, Personal Trainer
Personal training and fitness programs for clients in
Orange County, California including
Huntington Beach, Irvine, Mission Viejo, Aliso Viejo,
Laguna Niguel, and as far south as Coto de Caza
Copyright © 2008
Frank Moran. All rights reserved.