Nutrition and Exercise Quiz 1

9/2/26

Recommended Daily Allowance (RDA)

Meets the needs of nearly all healthy people in each gender and life stage; amount should be consumed daily

Adequate intake (AI)

the recommended average daily nutrient level assumed to be adequate for all healthy people

Tolerable Upper Level (UL)

the highest intake of a nutrient without risk of adverse effects to health

Acceptable Macronutrient Distribution Range (AMDR)

Used for energy-yielding macronutrients; expressed as a percentage of total energy

Baseline prescription for recommended exercise/week for health improvements

minimum of 150 min/wk moderate intensity

Health benefits of routine chronic aerobic exercise and resistance training

Decrease chances of: cancer, osteoporosis, hypertension, type II diabetes, overweight/obesity, cardiovascular related diseases

Increase: muscle mass, bone density, aerobic and anaerobic enzyme concentrations and activity levels, mitochondrial density and volume, capillary density, left ventricle chamber size and strength

5 components of fitness

1. cardiorespiratory endurance

2. muscular endurance

3. muscular strength

4. flexibility

5. body composition

specificity

training adaptions and performance are specific to the mode, intensity, and duration of the training regime; training must match goal

overload

to see improvements increase training load

reversibility

fitness gains will decline when training stops

overreaching

exercise fatigue to the point of no gains and lowered performance

overtraining

excessive training results in no further improvements in performance and likely performance decrements

periodization

training over smaller blocks of time allows for the intensity of training required for a performance outcome while also allowing adequate rest and recovery

cardiorespiratory endurance

a measurement of how well your heart, lungs, and muscles work together to keep your body active over an extended period of time

flexibility

the ability to move through a joint’s range of motion

muscular strength

the maximum force that can be generated by a muscle in a single contraction

muscular endurance

the ability of a muscle to sustain repeated contractions against resistance over an extended period of time

body composition

the proportion of the body that is fat versus that made up of other components (muscle)

detraining

when training is discontinued, training gains will be lost

Chemical energy is used for:

1. Protein synthesis

2. ATP formation

3. Glycogen storage

4. Adipose storage

Anabolism

“growth”; uses energy to synthesize building blocks to produce new molecules

Catabolism

breakdown of molecules to generate useable energy; muscle cells further catabolize glucose units in metabolic pathways occurring in the cytosol and mitochondria of the cell to produce ATP to fuel muscle contraction

TCA cycle (Kreb’s cycle)

within mitochondrial matrix;

accept metabolites from the cytosol as pyruvate, fatty acids, and amino acids following oxidization to form acetyl-CoA

follows glycolysis; acetyl-CoA comes in; NADH, FADH2, and ATP comes out

Electron Transport Chain (ETC)

series of complex protein channels that accept the electrons from the coenzymes; harnesses energy to fuel the final step in ATP formation, known as oxidative phosphorylation

Glycolysis

transforms 1 glucose to 2 pyruvate with a net gain of 2 ATP and 2 NADH; occurs in cytosol of the cell; does not require oxygen (anaerobic); ATP begins process then pyruvate converted to acetyl-CoA

Coenzyme A

attaches to fatty acids to enter the mitochondria; 1 molecule of ATP needed

Beta-oxidation

free fatty acids enter mitochondria and beta-oxidation removes 2 carbons to produce acetyl-CoA to enter the TCA cycle

FFA + CoA + ATP =

AcylCoA +AMP + pp

Alcohol

organic compound with hydroxyl group; first converted to acetaldehyde which is extremely toxic and reactive; liver gets rid of alcohol to prevent destroying cells and organs

most acetyl-CoA from alcohol forms fat;

alcohol → acetaldehyde → acetate → Acetyl-CoA

alcohol postexercise impairs muscle protein synthesis and suppresses antidiuretic hormone leading to dehydration

Triglycerides

3 carbons, 3 hydroxyl groups, and 3 free fatty acid chains

Deamination

amino acids stripped of their nitrogen component to enter TCA cycle at many breakdown points

transamination

moves amino group from an amino acid to an a-keto acid

Cross-over concept

as exercise intensity increases from low to high, somewhere in the increase a person will shift to using more carbohydrates than fat

Gluconeogenesis

creates glucose for the body from noncarbohydrate precursors (amino acids, lactic acid, and glycerol)

Glycogenesis

assembles glucose molecules into branched chains for storage as glycogen

Glycogenolysis

the breakdown of glycogen to glucose

Glycolysis

breakdown of glucose into 2 pyruvate

Lipogenesis

accelerated during times of excess calorie consumption; often leads to the gain of fat tissue

Calorimetry

general measurement of energy expenditure

direct calorimetry

measures heat production by the body

indirect calorimetry

determines energy expenditure without directly measuring the production of heat

Benefits of chronic endurance training

increased: left ventricle chamber size (stroke volume), mitochondrial size and numbers, aerobic enzymes of beta-oxidations, TCA, and ETC systems, angiogenesis (increased capillary density/growth), lactic threshold

improved: electron shuttle system (NAD and FAD shuttle systems), fatty acid transport into the mitochondria

Carnitine

transports Acylcarnitine inot mitochondrial matrix to form acylCoA for beta-oxidation and entering the TCA

simple carbohydrates

monosaccharides: glucose, fructose, galactose

disaccharides: maltose, sucrose, lactose

oligosaccharides

3-10 monosaccharides

polysaccharides

more than 10 monosaccharides

polysaccharides categories

starch, fiber, glycogen

starch

chains of glucose with alpha bonds can be broken-down; amylose and amylopectin

amylose

straight chains of glucose

amylopectin

branched chains of glucose

fiber

like starch but with beta bonds so cannot be broken down

soluble fiber

in GI tract, turns to gel via absorbs water, slows absorption

insoluble fiber

plant walls and structure, cannot be broken down; softens stool and increases waste removal via a scraping effect on GI tract

Glycogen

more branched than starch and stored in skeletal muscles and liver

glucose metabolism

1. blood glucose

2. glycolysis in cells for ATP

3. glycogen stores: muscle and liver

4. Converted to free fatty acids and stored in adipose cells

Normal Fasting glucose

1. 70-100 mg/dl = euglycemia

2. 100-125 mg/dl - prediabetes (fasting)

3. >126 mg/dl = diabetes mellitus (fasting)

Blood glucose cannot cross cell membrane

beta cells of pancreas release insulin which binds to cell membrane receptor that activates transporter proteins in cytoplasm (mainly GLUT 4) to move to cell membrane for glucose transport into cell

does not require insulin in the brain, some liver cells, and in skeletal muscles during exercise

insulin dependent glucose transporter (IDGT)

Type I diabetes mellitus

beta cells damaged/destroyed; no insulin is produced (autoimmune disease); need insulin injections (exogenous insulin)

Type II diabetes mellitus

cells are resistant to insulin; increase insulin with glucose; beta cells “wear-out” and no longer secrete insulin; need insulin injections

decrease blood glucose

increase in glucagon thus increasing gluconeogenesis and glycogenolysis in the liver

two gluconeogenic pathways

alanine and cori cycle

Alanine

glucose cycle; BCAAs (branched-chain amino acids) in muscle deaminated (remove amino group) and oxidized → NH2 added to pyruvate in muscle becomes alanine (transamination) → alanine to liver deamination back to pyruvate and NH2 → NH2 converted to urea, pyruvate to glucose

cori cycle

converts lactate to glucose in the liver

epinephrine and norepinephrine

stimulate glycogenolysis

cortisol

simulates gluconeogenesis

Triglycerides

most abundant form of lipids (insoluble in water); consists of glycerol bonded to 3 FFAs

saturated fatty acids

solid at room temp

unsaturated fatty acids

liquid at room temp; have kink at carbon to carbon double bonds that do not allow them to “stack” on each other thus slide past

polyunsaturated fatty acids (PUFAs)

named for carbon # with double bond from the methyl end (CH3)

Unsaturated fatty acids

cis configuration with H bond on same side of C=C (double bond)

Trans unsaturated fatty acids

H opposite side of C=C bond; no consumption is best

FFA

short 2-6 carbon

medium 7-12 carbon

long more than 12 carbon - need carnitine to transport into mitochondria

FFA range from 2-40 carbon length; however, most 12-40 carbons

linoleic and alpha-linolenic acids are essential fatty acids

Liver can produce all FFAs from fat, glucose, and proteins except Linoleic acid (LA) an omega 6 fatty acid and Alpha-Linolenic Acid (ALA) an omega 3 fatty acid

ALA can be converted to EPA and DHA

Sterol

compounds with multiple rings in plants and animals

cholesterol

a type of sterol in animal-based foods only;

needed to form steroid hormones e.g. testosterone, estrogens, etc.

too much related to atherosclerosis

phospholipid

glycerol with a phosphate and a free fatty acid

large portion of cell membranes

lipoprotein is a type of phospholipid used to transport cholesterol and fat in the blood

saturated fatty acids

no intake requirement, help form cell membrane, can be related to atherosclerosis via increase in LDL

when replace with PUFA’s decrease LDL and increase insulin sensitivity with reduction in heart attacks and fatal heart attacks

replace with MUFA’s decrease chance of CV disease but not as effective as PUFA’s

MUFA’s (monounsaturated fatty acids)

body can produce; can decrease total and LDL cholesterol, triglycerides, and increase HDL

PUFA’s (polyunsaturated fatty acids)

omega 6 essential is LA

omega 3s including ALA, EPA, DHA, and SDA

ALA precursor for EPA and DHA

EPA

decrease heart attacks, strokes, and inflammation

DHA

found in brains and important for brain functioning; decrease inflammation

EPA and DHA

decrease blood pressure and triglycerides; increase HDL and decrease chance of CHD and heart attacks

Trans fatty acids

predominately man made from partially hydrogenated oils; however little naturally made in some dairy products

decrease HDL increase LDL with decease in LDL particle size; no recommended intake

No daily recommended intake for EPA and DHA

WHO recommends 250 mg/day

AHA recommends two 35-unce servings fatty fish/week

Chylomicrons

long-chain fatty acids formed into a type of lipoprotein; triglyceride transporters

lipoprotein lipase breaks-down into FFAs

medium and short chain FFAs not formed into chylomicrons

Lipoprotein lipase breaks-down triglycerides from lipoproteins in blood

mono and diglycerides are delivered to adipose tissue and reassembled into triglycerides for storage

proteogenic

amino acids ability to form proteins

23 AA can build proteins, 20 used to form all human structures

amino acids (AA)

NH2 and COOH

3 amino acids branch chain

valine. leucine. isoleucine

branched chain amino acids

functional group of AAs that the muscle can directly oxidize to ATP

stimulate muscle protein synthesis

AA pool

AA in blood and liver more AAs recycled than consumed

AA broken down

ATP and amino group (NH2) which liver converts to NH3 (ammonia)

NH3 combined with CO2 produces water and urea in the kidneys

Dipeptides

two AAs with covalent bond b/w carboxyl group (COOH) and amino group (NH2) via dehydration synthesis

Tripeptides

three bonded AAs

Polypeptides

more than 10 AAs can be 100s long

Proteins

10 to 1000s AAs long

Protein catabolism

large quantities of AAs are recycled in AA pool

after deamination enter 3 points in metabolic cycle

1. cytosol as pyruvate

2. mitochondria as acetyl CoA

3. an intermediate of the TCA cycle

Amino group (NH2) removed in liver and forms:

1. glucose

2. free fatty acids

complement proteins

combo of plant-based foods that collectively provided all the essential AAs (EAA)

High quality proteins

amount and combo of EAAs including digestibility, bioavailability including other AAs

Protein intake level for increasing muscle mass

1.2-2.0 grams/kg body weight