carbohydrates, lipids, and proteins
what are the three macronutrients
glucogenesis
the synthesis of glycogen from glucose is what?
(glucose-->glycogen)
gluconeogenesis
glucose synthesis largely from structural components of noncarbohydrate nutrients
(protein-->glucose)
glycogenolysis
glucose formation from glycogen
(glycogen-->glucose)
carbohydrate (CHO)
converted to glucose
monosaccharides
one sugar
disaccharides
two sugars
polysaccharides
multiple sugars
glycogen
storage carbohydrate in muscle and liver
2000 kcal
body stores about _____ as carbohydrates
400g
muscle stores about ____ glycogen
90-100g
liver stores about ______ glycogen
15g/kg BW
upper limit for glycogen storage averages about ____
fuel mixture
intensity and duration determine _____
lipids (fats)
provides substantial energy at rest (2/3 of kcal) and during prolonged intense aerobic activities
55%
1 hour of short-distance exercise decrease liver glycogen by _____
fat
what serves as the main energy substrate during low-intensity exercise?
falls, increases
as sub maximal activity progresses in a glycogen depleted state, blood glucose _____ and circulating free fatty acids _____.
Lipolysis
breakdown of fat into glycerol and 3 FFA's
simple lipids
-consist primarily of triacylglycerol (TAC's)
-primary storage form (adipocytes)
compound lipids
-TAC's bound with other structures
-Functions: maintain cell integrity and manipulates fluid movement across cell membranes
Derived lipids
trans fat
saturated fatty acids
carbon binds to the maximum number of hydrogens
-no double bonds, fit close together
-occur primarily in animal products and some plants
unsaturated fatty acids
-monounsaturated contain 1 double bond
-polyunsaturated contain 2 or more double bonds
an example of essential fatty acid
what is linolenic acid?
1. low-to-moderate-intensity physical activity
2.low-calories dieting or fasting
3.cold stress
4.prolonged exercise that depletes glycogen reserves
4 conditions of mobilization of fatty acids via lipolysis
glycolipids
fatty acids bound with carbohydrates and N2
lipoproteins
protein molecule joined with a triacylglycerol or phospholipid
chylomicrons
transport Vitamins A,D,E, and K
High-density lipoprotein (HDL)
good" cholesterol
very low density lipoproteins (VLDL)
transport TAG's to muscle and adipose tissue
low-density lipoprotein (LDL)
bad" cholesterol
insulation, protection, shock absorber, energy reserves, vitamin/hormone transporter
why do we have fat?
light-intensity exercise
fatty acids provide predominant energy source in ______
moderate-intensity exercise
energy derives from equal amounts of carbohydrate and lipid in _______
high-intensity exercise
energy derives from carbohydrate, primarily muscle glycogen in _____
improves, mild-to-moderate
regular aerobic exercise profoundly _____ long-chain fatty acid oxidation, particularly TAG to active muscle to ______ exercise
true
T/F: percentage contribution of macronutrient catabolism relates to oxygen uptake of leg muscles during prolonged exercise
proteins
______ are constructed from amino acids and contain 16% nitrogen
dipeptide
two amino acids linked together
tripeptide
three amino acids linked together
polypeptide
50 to more than 1000 amino acids joined together
essential amino acids
indispensable, body cannot synthesize them so they must be consumed in food
nonessential amino acids
body can synthesize from other compounds already in body tissues at a rate to meet growth and tissue repair needs
complete proteins
exist in foods that contain all the essential amino acids in the quantity and correct ratio to maintain nitrogen balance
incomplete proteins
lack one or more essential amino acids
catabolism
nitrogen must be removed from amino acids prior to ______
Deamination
nitrogen removal, forms urea that is eliminated as urine
increase
most modes and intensities of exercise modestly ______ protein breakdown
increases
large _______ in protein synthesis occur during recovery from endurance and resistance exercise
micronutrients
significant roles to facilitate energy transfer and tissue synthesis
Fat soluble vitamins
A, D, E, K
-high doses can be toxic b/c it gets stored in the fat tissue
water soluble vitamins
C and B-complex
-act largely as coenzymes in metabolism
False
-they serve as essential links and regulators in metabolic reactions
-control tissue synthesis and protect the integrity of the cells plasma membrane
T/F: vitamins contain a lot of useful energy
intense physical activity
oxidative stress increases with _____
Regular aerobic exercise
lessens the likelihood of tissue damage from intense physical activity
Antioxidants
help neutralize vitamins and limit DNA damage
-hinder athletic performance
> 100 mg/d
7 major minerals required in amounts ____
< 100mg/d
14 trace minerals required in amounts ____
structure, function, regulate
-minerals provide ____ in forming bones and teeth
-help to maintain normal bodily______
-_________ metabolism by becoming part of enzymes and hormones that modulate cellular activity
calcium
what is the body's most abundant mineral
osteopenia
weakened bone, increasing fracture risk
osteoporosis
bone loses it's calcium mass and concentration, which causes bone to progressively become more porous and brittle with high likelihood of fracture
sodium, potassium and chlorine
what vitamins are known as electrolytes
chief minerals
sodium and chlorine represent the ______ contained in blood plasma and extracellular fluid
chief intracellular mineral
potassium serves as the ________
body water loss and loss of related minerals with water replacement the crucial and immediate need
excessive sweating during exercise produces
replaced
body water and minerals must be _____ during and following exercises
not increase
sweat loss during exercise usually does _________ mineral requirements above recommended values
40-70%
water constitutes _____ of total body mass
70%
muscle contains _____ water
10%
fat contains ____ water
62%, 38%
_____ of the body's water occurs within cells and ___ occurs outside of cells in plasma
...
loss of body water represents the ______ consequence of profuse sweating
1.Physical activity intensity
2.Environmental temperature
3.Relative humidity
what factors determine the amount of water loss
450mL
Each 0.45kg body weight loss corresponds to _____ of dehydration
hyponatremia (water intoxication)
sustained low plasma sodium concentration creates an osmotic imbalance across the blood-brain barrier.
-swells brain tissues
headache, confusion, nausea and cramping
(severe ones are seizures, coma, pulmonary edema, cardiac arrest and death)
symptoms of hyponatremia
400mL-600mL
drink ______ fluid 2-3 hours before exercise
150mL-300mL
drink _____ fluid 30 minutes before exercise
during or after
drink no more than 1000mL of plain water spread over 15 min intervals _____ exercise
ATP-PCr system
-occurs in the cytoplasm of the cell
-fastest rate of ATP production
-shortest duration at which ATP can be produced
-provides energy for tasks that demand a lot of energy in a short period of time
(sprinters)
glycolytic system
-occurs in the cytoplasm of the cell
-moderate rate and duration of ATP production
oxidative system
occurs in the mitochondria of the cell
-slowest rate of ATP production
-longest duration at which ATP can be produced
-includes krebs cycle and ETC
-does require oxygen
(distance runners)
anaerobic
no O2 required
1
ATP yield (ATP-PCr): ____ ATP per PCr
increases, increases
when ATP levels decrease, ADP _____ and CK activity _____
decreases
when ATP levels increase, CK activity ______
creatine kinase
the enzyme used to split PCr into a phosphate and creatine
phosphate
______ is added to ADP to create ATP
-acts as a reservoir of high-energy phosphate bonds
availability of primary substrate, enzyme availability
energy is produced at a controlled rate based on_______
rate-limiting enzyme
controls rate of overall reaction
negative feedback
the end product of a process in turn reduces the stimulus of that same process
the investment phase
the first few reactions of glycolysis are referred to as ______
True
-aerobic --> pyruvate
-anaerobic --> lactate
T/F: Glycolysis can be both aerobic and anaerobic
increase, increase
A decrease in ATP causes a ____ in ADP and ____ in PFK activity
decrease
An increase in ATP causes a _____ in PFK activity
decrease
when pH levels go down, PFK will _____
1, 0
In glycolysis it costs ___ ATP for glucose and ___ ATP for glycogen
2, 3
Glycolysis net ATP yield: ____ ATP for glucose and ___ ATP for glycogen
aerobic
oxygen required
1, 32-33
Oxidative system: ___ glucose= ____ ATP
1, 100+
oxidative system: ___ FFA=_____ATP
Stage 1: glycolysis
Stage 2: Krebs Cycle
Stage 3: electron transport chain
what are the steps of the production of ATP?
Acetyl-CoA
what is the first substrate in Kreb's Cycle?
B-oxidation of fat
-breakdown of fats into energy
-converting FFA's to acetyl-coq before entering the Kreb's Cycle
-every time you go through this cycle, you cut off 2 carbons
Acetyl-CoA
_____is the common entry point for carbohydrates, fat and proteins
-2-3 ATP
-2 NADH, pyruvic acid or lactate
what is the output of glycolysis?
creatine kinase
what enzyme is necessary to ATP from PCR?
high intensity exercise
oxygen debt is highest after _______
60 to 180 s
rapid and large accumulation of blood lactate occurs during maximal exercise of ________
True
T/F: lactate threshold can change with training
aerobic metabolism
steady rate _______ reflects a balance between energy required by working muscles and ATP production in aerobic reactions
oxygen deficit
Difference between total oxygen consumed during exercise and the total that would have been consumed had steady-rate oxygen uptake been achieved at the start of exercise
true
T/F: endurance-trained individuals have a smaller oxygen deficit
EPOC (oxygen debt)
total recovery VO2 MINUS total VO2 theoretically consumed at rest during recovery
1. level of anaerobic metabolism during activity
2. respiratory, circulatory, hormonal, ionic and thermal adjustments that elevate metabolism during recovery
what factors impact recovery VO2?
active recovery
-cooling down or tapering off
-includes sub maximal exercise may prevent muscle cramps and stiffness and facilitate overall recovery
passive recovery
individual lies down with minimal energy expenditure (which is believed to reduce recovery energy requirements and thus "free" oxygen to fuel the recovery process); modifications include massage, cold showers, specific body positions, and consuming cold l
1000
1 kcal = _____cal
40%
only about _____ of the energy liberated during the metabolism of glucose and fats is used to produce ATP
-remaining 60% is converted to heat
metabolic rate
rate at which the body expends energy at rest and during exercise
-typically measured at rest
resting metabolic rate
the minimum energy required for essential physiological function
-varies between 1200-2400 kcal/24hrs
-60-75% of daily energy used
PFK
what is the rate-limiting enzyme in glycolysis?
Acetyl CoA
what is the common starting point of the Kreb's Cycle?
ATP-PCr system
which does not provide NADH to the ETC?
3
the Kreb's cycle produces ____ NADH
1
Beta-Oxidation produces ____ NADH
thermic effect on a meal (TEM)
energy used for digestion, transport and metabolism of ingested food
-10% of daily energy used
thermic effect of activity (TEA)
-energy above RMR needed to perform activities
-15-30% of daily energy used
-effected by duration, intensity, size of individual and body mass
body weight, age, weight loss
what factors affect resting metabolic rate?
direct calorimetry
using the principle that energy given off in the form of heat
indirect calorimetry
a method of estimating energy expenditure by measuring respiratory gases
mitochondria
oxygen is used in the _____ to make ATP
respiratory quotient (RQ)
the ratio between volume of CO2 produced in metabolism (VCO2) and volume of oxygen consumer (VO2)
RQ=VCO2/VO2
what is the equation for RQ?
0.80
what is the RQ value typically at rest?
glucose
when O2 is limited, _____ is the preferred duel because it is more efficient
true
T/F: glucose is a limited fuel source while fat is not so fat is preferred during low intensity activities
increases
as exercise intensity _____, RQ increase
increases
energy expenditure ______ when you start exercising
2/3 fat and 1/3 CHO
shifts in substrate utilization during rest
1/3 fat and 2/3 CHO
shifts in substrate utilization during exercise
respiratory exchange ratio
reflect the ratio of CO2 produced to O2 consumed when factors other than food combustion contribute to gas exchange
-indicates that pulmonary exchange of O2 and Co2 no longer reflect only cellular oxidation of specific foods
excess CO2 production in relation to O2 uptake (lactate)
what does an RER of greater than 1 indicates?
exercise economy
the caloric cost to produce movement at a specified intensity
hyperventilation
increases CO2 to higher levels compared to current metabolic demands
buffering
produces the weaker carbonic acid during intense exercise, which degrades to CO2 and H2O with the lungs readily spelling CO2
VO2 max
the maximal capacity for oxygen consumption by the body during maximal exertion
-single best measurement of cardiorespiratory endurance and aerobic fitness
-40m dash, high jump, olympic lifts, shot put, long jump, ski jump
how can we test the immediate energy system? (ATP-PCr)
400m dash, hockey, diving, gymnastics (except vault)
how to we test the glycolytic system?
wingate test
30s super maximal effort on leg or arm cycle ergometer
-initial resistance set to 0.075 kg/BW; resistance increased after overcoming
blood lactate
level provides most common indicator of activation of short-term energy system but it may not necessarily reflect absolute levels of anaerobic energy transfer via glycolysis
glycogen depletion
depleting pattern can reveal glycolytic contribution to power the short-term energy system
VO2 Max, capillary desnity, level of aerobic enzymes, mitochondrial size and number and muscle fiber type
what are the determinants of endurance power
Absolute VO2 max
how much oxygen you use
-L/min
Relative VO2 max
this is how much oxygen you use relative to your body size
44-50
VO2 max of untrained young men?
38-42
VO2 max of untrained young women
VO2 peak
highest value of oxygen consumption measured during a graded exercise test
-if you don't see the plateau
-only occur if the person is not able to push through the exercise
10%
only about _____ of the lungs are solid tissue
aveoli
site of gas exchange between lung tissue and blood
-increase the surface area for gas exchange to occur
surfactant
a solvent that prevents water from binding so when you breathe in you're not working against the natural pressure from the water
conducting zone
-trachea and terminal bronchioles
-brings the air in from the atmosphere
-anatomical dead space
transitional
...