honors exercise physiology manuscript

8/9/2019 Honors Exercise Physiology Manuscript

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Justin Zeien

Mr. Olson

Honors Exercise Physiology/ 5

29 March 2010

Honors Exercise Physiology Manuscript

Chapter 1:

1. An exercise response is the pattern of change that physiological variables exhibit during a

single acute bout of physical exertion. Exercise modality, exercise intensity, and exercise

duration need to be considered to determine the exercise response. Training adaptations

are the physiological changes or adjustments resulting from an exercise training program

that promote optimal functioning. While exercise responses use resting values as the

baseline, training adaptations are evaluated against the same condition as opposed to

training. Training adaptations essentially improve the exercise response of an exerciser as

compared to the exercise response of an untrained exerciser.

2. An absolute submaximal workload is a set exercise load performed at any intensity from

just above resting to just below maximum. An example of an absolute submaximal

workload would be the whole class running a mile as fast as they could. A relative

submaximal workload is a workload above resting but below maximum that is prorated to

each individual; typically set as some percentage of maximum. An example of a relative

submaximal workload would be the whole class running a mile at 85% of their maximum

speed.

3. One example of an exercise situation would be a long-term, moderate to heavy

submaximal aerobic exercise. Although being a predominantly aerobic exercise, this


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occurred, respectively. Reversibility is the reversal of achieved physiological adaptations

that occurs when training stops otherwise called detraining. Maintenance is the

sustaining of the achieved adaptation with the most efficient use of time and effort. The

amount of time and effort required to maintain the individuals adaptation depends on the

systems involved and the intensity of the exercises. As long as intensity is maintained,

frequency and duration can be decreased without losing positive adaptations.

Individualization is the idea that individuals both require personalized exercise

prescriptions based on their fitness levels and goals and they adapt differently to the same

training program. Factors of individualization are lifestyle, food intake, sleep habits,stress levels, substance use, age, sex, gender, and disease conditions. Warm-Up/Cool-

Down are essential for exercise. A warm-up prepares the body for activity by raising the

body temperature while a cool-down allows for a gradual return to normal body

temperature.

5. Tennis

General preparation phase: aerobic base-100 meter sprints, run the mile, stadium

running; heavy resistance-lift weights to increase arm and shoulder strength, squats and

heavy resistance leg extensions to build muscular strength in legs as well as muscular

endurance; flexibility-lots of PNF stretching, yoga; attain % body fat-attain 10% body fat

for maximal speed and lateral quickness when running after ball, eat healthy and all-

natural foods with 60-70% carbohydrates, 25% protein, and the rest vitamins, minerals,and fats

Specific preparation phase: high-intensity sport-specific-work on tennis strokes,

frog jumps to increase vertical power, long shuffle exercises to improve lateral quickness,


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bench press and pectoral fly to increase muscular strength in primary muscles responsible

during tennis, many 50 meter sprints to build fast-twitch muscle in order to improve

quickness during tennis points,

high duration runs for miles to

build endurance for long tennis

matches

Competition phase: league

play/school team play and

championships Transition phase: cross-

training- swimming, cycling, stair

climber, take days off to rest

6. Overtraining is a state of overstress or failure to adapt to an exercise training load.

Performance-related signs would be that the muscles would be too fatigued to perform to

the same level that is typical of them. The level in performance would decrease over time

instead of increase as it naturally should. Retrogression, plateaus, and reversibility can all

be early signs of overtraining. Too much time and effort spent on the same workout under

the same conditions (environment, machine type, etc.) can lead to a plateau.

Physiological signs can be vomiting, fainting, dizziness, nausea, lightheadedness, and

weakness and fatigue of the overworked muscles. Behavioral signs could consist of

crankiness, tiredness, exhaustion, and ill-humor.


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Chapter 10:

1. Pattern A: (600 mL/br)-(150 mL/br)(10 br/min)= 4500 mL/min

Pattern B: (200 mL/br)-(150 mL/br)(30 br/min)= 1500 mL/min

It is better and more efficient to breathe slowly and deeply.

2. Both situations decrease alveolar ventilation. By only inhaling new air without first

exhaling the old air, the individual will be unable to inhale as much oxygen and they will

not have as much new oxygen to utilize. If they exhale and inhale quickly in a short

period of time, the body does not have ample time to completely rid the lungs of the

spent air and fully replace it with fresh oxygen. The individual is slowly suffocatingthemselves by not exhaling the air first then inhaling above water to achieve maximum

inhalation of fresh air rich with oxygen. The volume of the dead space has a negative

impact on the amount of air available for exchange.

3. A snorkel extends the dead space. The tidal volume must be increased enough so that it

compensates for that volume as well as the anatomical dead space to maintain effective

alveolar ventilation.

4. Pulmonary ventilation is the process by which air is moved into the lungs. External

respiration is the exchange of gases between the lungs and the blood. Internal

respiration is the exchange of gases at the cellular level.

(A-a)PO2diff : the difference in the partial pressure of oxygen between the

alveoli and the arteries, external respiration a-VO2diff : the difference between the amount of oxygen returned in venous

blood and the amount originally carried in arterial blood, external respiration

VD : dead space, internal respiration and pulmonary ventilation


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F : frequency (breaths/min), pulmonary ventilation

VE and VI : the amount of air inspired or expired each minute; the pulmonary

ventilation rate per minute; calculated as tidal volume multiplied by the frequency of

breathing

VT : the amount of air that is inspired or expired in a normal breath, pulmonary

ventilation

PaO2 : partial pressure of oxygen in the arteries, external respiration

PAO2 : partial pressure of oxygen in the alveoli, internal respiration

PaCO2 : partial pressure of CO2 in the arteries, external respiration

PvCO2 : partial pressure of CO2 in the veins, external respiration

PvO2 : partial pressure of oxygen in the veins, external respiration

SaO2% : percent saturation of hemoglobin for arterial blood, external respiration

SbO2% : the ratio of the amount of hemoglobin combined with oxygen to the

total hemoglobin capacity for combining with oxygen, external respiration

SvO2% : percent saturation of hemoglobin for venous blood, external respiration

5. Air flows into and out of the lungs because of the pressure gradient

formed from the lungs and the outside environment. Gases naturally move from areas of

high pressure to areas of low pressure. Inspiration takes place because the pressure is

higher in the atmosphere than in the lungs and expiration occurs because the pressure is

higher in the alveoli of the lungs than in the atmosphere. Boyles law states that the

pressure of a gas is inversely related to its volume under conditions of constant

temperature. Low pressure is associated with large volume and high pressure is


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associated with small volume. The lungs capture the O2 and transport it to the heart for

diffusion. Then the lungs discard the CO2 that the body has already used.

6. Total lung capacity can be divided into four different volumes-

inspiratory reserve volume (IRV), tidal volume (VT), expiratory reserve volume (ERV),

and residual volume (RV). Total lung capacity can also be divided into three different

capacities-inspiratory capacity (IC), functional residual capacity (FRC), and vital

capacity (VC). IRV and ERV are the most responsive during exercise. RV has to be

accounted for during hydrostatic weighing because it is impossible to empty the lungs of

all of its oxygen even after a maximum exhalation.7. Oxygen is carried two ways into the blood. The first way oxygen is

transported is in a dissolved form in the liquid portion of the blood. The amount of

oxygen transported via this way is only about 1.5-3% of the total oxygen transported. The

second way oxygen is transported in the blood is bound to the hemoglobin. 97-98.5% of

the oxygen is transported in the bloodstream bound to hemoglobin. Carbon dioxide on the

other hand, is carried three different ways in the bloodstream. The first way is carbon

dioxide is dissolved in blood plasma and only 5-10% of the total CO2 is transported in

this way. The second way CO2 is transported is chemically attached to the globin portion

of the Hb molecule which is called carbamino hemoglobin. This method of transportation

accounts for 20% of the CO2 transportation through the circulatory system. The third

way CO2 is transported is as bicarbonate ions. 70-75% of the CO2 is transported in this

way. When the CO2 diffuses with the RBCs, it combines with water to form carbonic

acid which quickly breaks up into hydrogen ions and bicarbonate ions. Once back in the


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conscious thought like entrainment does. Subjects forced to breathe in specific

entrainment patterns rather than being allowed to breathe spontaneously do not show any

reduction in energy cost nor perceive any decrement in breathing effort with entrained

breathing. This means that entrainment should only be used if it comes naturally to the

individual during exercise because when entrainment is forced, there are not the same

benefits as natural entrainment. The best advice for land activity is to breathe in whatever

way comes naturally and feels the best. The exception is weight lifting where blood

pressure raises if specific entrainment breathing is not used.

3. EIH is a condition in which the amount of oxygen carried in arterial blood is insufficient. This condition occurs only in high trained elite athletes because

respiration, more specifically external respiration, is a limitation to exercise in some

highly trained athletes. Athletes who exhibit EIH at sea level suffer more severe gas

exchange impairments during short-term exposure to higher altitudes than do athletes

who do not exhibit EIH at sea level. The factors of EIH are that a relative hypoventilation

induced by endurance training may be involved if the EIH occurs at moderate sub-

maximal exercise intensities. At higher intensities, both theoretical and experimental

evidence support an inequality between respiratory ventilation and circulatory perfusion

as one reason and a limitation in diffusion as another. In normal or moderately trained

individuals, pulmonary capillary blood volume increases with exercise which increases

the surface area for diffusion and slows down the red blood cell transit time to allow

complete diffusion and equilibration of the gases. On the other hand, the pulmonary

capillary blood volumes of highly trained athletes reaches its maximum at relatively low

workloads so when elite athletes continue to increase their workloads and total body


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circulation, pulmonary capillary volume cannot expand anymore. Blood flow velocity

increases and red blood cell transit time decreases instead. The red blood cell transit time

in elite endurance athletes is estimated to be less than that required for gas equilibration

which entails that EIH may be attributed in part to a diffusion limitation as a consequence

of this reduced red blood cell transit time.

4. Hypoxic training is not beneficial because altitude training is only

beneficial for competition at altitude, not at sea level. Controlled-frequency breathing

does not produce hypoxia but instead, produces hypercapnia which is an increase in the

partial pressure of CO2. Hypercapnia causes headaches for 30 minutes or more after exercise and are extremely painful and may interfere with training.

Chapter 12:

1. LVEDV=150, SV=80 mL/b. LVEDV=200, SV=100 mL/b.

LVEDV=250, SV=105 mL/b.

2. EF=80/150=53%. EF=100/200=50%. EF=105/250=42%

3. Mike: Q=7.2 L/min. Sharon: Q=7.2 L/min. Kirk: Q=17.87 L/min. Don:

SV=88.05 mL/b. Nora: HR=58 b/min

4. The heart contains specialized

conducting cells that are essential because they spread the

electrical signal quickly throughout the myocardium. The

excitation is spread from the SA node throughout the

right atria by internodal tracts and to the left atria by

Bachmanns bundle. The signal is then spread from the

atria to the ventricles via the AV node. After depolarization of the AV node, the electrical


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signal continues down the specialized conduction system consisting of the bundle of His,

the left and right bundle branches, and the Purkinje fibers. The electrical excitation then

spreads out from the conducting system to excite all of the myocardial cells.

5. VEP occurs during ventricular diastole when the AV valves are open.

Diastole continues with the ventricles filling with blood as the blood is returned to the

atria and flows down into the ventricles. Atrial contraction also pushes a small volume of

blood into the ventricles at the end of diastole. Blood volume in the ventricles is the

greatest at the end of ventricular filling, but pressure remains relatively low because the

ventricles are relaxed. During the ICP period of systole, both the AV valves andsemilunar valves are closed. Blood volume in the ventricles remains constant despite the

high pressure generated by the contraction of the ventricular myocardium. Once pressure

in the ventricles exceeds pressure in the aorta, the semilunar valves are forced open.

Blood is then ejected from the ventricles causing ventricular volume to decrease. As a

result, isovolumetric relaxation period begins with the AV and semilunar valves both

closed. Ventricular volume is unchanged and the pressure is low because the ventricles

are relaxed.

6. VO2max is the greatest amount of oxygen that the body can take in,

transport, and utilize during heavy exercise. Since the body relies on the respiratory

system to bring in the oxygen from the environment, the cardiovascular system has to

transport the oxygen. The cells are responsible for extracting the oxygen and using it in

the production of energy. The assessment of the VO2max provides a method for

quantifying the functional capacity of the entire cardiovascular system. It is often

considered the single most important variable in describing an individuals fitness level


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and is routinely used to describe an individuals cardiorespiratory capacity. VO2max

basically tells everyone how strong your heart and lungs are when they work together

during heavy exercise. Every process in the body speeds up to accommodate for the

bodys increased demands and accordingly, the heart and lungs need to work together at

their optimal levels in order to supply the muscles with enough oxygen to continue

performing.

7. There are many possible factors that could limit maximal oxygen

consumption since it theoretically could be limited by any system along the pathway of

bringing oxygen into the body and delivering it to the mitochondria for the production of ATP. More specifically, possible systems that limit VO2max are the respiratory system,

cardiovascular system, and the metabolic functions within skeletal muscle. For the

respiratory system, it limits VO2max due to oxygen diffusion limitations, inadequate

ventilation, or an inability to maintain the gradient for the diffusion of O2. The

cardiovascular system limits VO2max because of inadequate blood flow or oxygen-

carrying capacity. The metabolic functions within skeletal muscle limit VO2max, such as

an inability to produce additional ATP, because of limited number of mitochondria,

limited enzyme levels or activity, or limited substrates. The most likely factor limiting

maximal oxygen uptake is the ability of the cardiorespiratory system to deliver oxygen to

the muscle, rather than the ability of the muscle mitochondria to utilize oxygen. The

cardiac output is the limiting factor in VO2max.

8. 1. The arm is measured and a proper cuff size is chosen. The cuff is

secured around the upper arm and the stethoscope is placed just below the antecubital

space over the brachial arterial. 2. The blood pressure cuff is inflated to a pressure greater


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than systolic blood pressure (usually around 140 mmHg at rest), using the inflation bulb.

3. The pressure inside the cuff is very slowly released (at the rate of 2 or 3 mmHg per

second), using the release valve attached to the inflation bulb. When the pressure falls

just below the systolic blood pressure, blood flow resumes and can be heard through the

stethoscope with each heartbeat. The sounds heard are called Korotkoff sounds and the

pressure at which the first Korotkoff sound is heard represents the systolic blood

pressure. 4. Continue releasing the pressure inside the cuff. When there is a muffling in

the Korotkoff sounds, this is taken to be the fourth Korotkoff sound which represents the

first measure of diastolic blood pressure. The disappearance of the Korotkoff soundsrepresents the fifth Korotkoff sound and indicates the second measure of diastolic blood

pressure.

Chapter 13:

1. All graphs, except for DBP and TPR, increase and then level out. The TPR graph

decreases, then levels out. The DBP line in the BP graph stays constant all the way

through. There is an initial increase in cardiac output to a plateau at a steady state. The

plateau within the first 2 minutes reflects the fact that cardiac output is sufficient to

transport the oxygen needed to support the metabolic demands of the activity. The

increase in stroke volume results from an increase in venous return, which, in turn,

increases the LVEDV. Heart rate increases immediately at the onset of activity as a result

of parasympathetic withdrawal. SBP has an initial increase and a plateau once steady

state is achieved. The increase in SBP is brought about by the increase in cardiac output.

DBP remains constant because of peripheral vasodilation which facilitates blood flow to

the working muscles. The small rise in SBP and the lack of change in DBP cause the


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MAP to rise only slightly, following the pattern of SBP. TPR decreases owing to

vasodilation in the active muscles. The RPP will increase in relation to increases in heart

rate and SBP, reflecting the greater myocardium oxygen demand of the heart during

exercise.

2. The cardiac output graph increases significantly and then levels out. The heart has to

pump more blood and oxygen for the muscles which are under more stress. For the blood

pressure graph, the systolic blood pressure line increases then begins to decrease slowly,

the MAP graph increases, levels out, then has a little dip, and then levels out again. The

DBP line remains constant all the way through. During systole, the heart has to push

blood out through the arteries at a higher pressure in order to supply the muscles with

enough oxygen to continue functioning. The MAP increase is due to the increase in the

pressure of the arteries as the heart works and pushes harder to send enough blood out

through the arteries. The SV graph increases, levels out, and then deceases slowly. Stroke

volume plateaus at a max level after a workload of approximately 40-50% of VO2max

has been achieved. The TPR graph decreases significantly then remains somewhat


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constant. This curvilinear decrease is because of vasodilation in the cutaneous vessels in

order to dissipate the heat produced by mechanical work. Both the heart rate and the RPP

graphs have a significant increase, level out, and then begin to slowly increase again.

Heart rate shows this response because the heart has to pump faster and at a higher

frequency to supply the muscles with enough oxygenated blood to continue performing at

that high level. Since the heart rate and systolic blood pressure increase substantially

during heavy work, the RPP increases as well. The high RPP value reflects the large

amount of work that the heart must perform to support heavy exercise.

3. All graphs except for TPR, MAP, DBP, and SV have a significant increase and then

begin to level out. MAP and SV increase for a little, then level out. DBP always remains

constant and TPR deceases significantly. Cardiac output displays a rectilinear increase

and plateaus at maximal exercise because of the dramatic increase in heart rate. Stroke

volume increases rectilinearly initially and then plateaus at 40-50% of VO2max. Heart

rate increases in rectilinear fashion and then plateaus at maximal exercise because the

myocardial cells rarely exceed over 210 beats per minute since a faster heart rate would


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Also, over time, the amount of blood and oxygen the muscles require slowly increases so

the cardiac output slowly increases to meet these demands. Stroke volume is relatively

constant at low workloads but it decreases at high workloads and has a rebound rise in

recovery. The reduction in SV during high-intensity contractions is probably the result of

both a decreased preload and an increased afterload. Heart rate increases during static

exercise. The magnitude and the rate of the increase in heart rate depends on the intensity

of contraction since the greater the intensity, the greater the heart rate response. Static

exercise also entails a rapid increase in SBP and DBP which is termed pressor response.

In static work results high intramuscular tension results in mechanical constriction of the blood vessels, which impedes blood flow to the muscle. The reduction in muscle blood

flow during static exercise results in a buildup of local by-products of metabolism which

cause a rise in all blood pressures, especially MAP. MAP also increases due to the simple

fact that there are increases in SBP and DBP. TPR decreases which helps explain the

higher blood pressure response to static contractions. The high blood pressure generated

during static contractions helps overcome the resistance to blood flow owing to

mechanical occlusion. Since there is a large increase in heart rate and SBP, there is a

large increase in RPP.


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5. Cardiac output has a modest gradual increase during dynamic exercise. Cardiac output at

the completion of the set was highest when the lightest load is lifted for the greatest

number of repetitions. Stroke volume shows very little change in dynamic exercise and

even may exhibit a slight decrease. This is contrasting to significant increases in stroke

volume measures during aerobic exercise and this data shows that dynamic resistance

exercise does not produce the stroke volume overload that dynamic endurance exercise

does. HR increases gradually as the number of repetitions increases. Heart rate is highest

after completion of the set using the lightest load and lifting it the greatest number of

times. Heart rate was lowest when the single rep using the heaviest weight was

performed. When the load is heavy, HR, MAP, and SBP increase gradually with

succeeding reps in a set to failure. The increase in these blood pressures results from the

mechanical compression on the blood vessels and performance of the Valsalva maneuver.

DBP remains constant because of peripheral vasodilation which facilitates blood flow to

the working muscles. TPR has a slight increase and is higher during dynamic resistance

exercise compared to dynamic endurance exercise. This is because of the

vasoconstriction caused by the pressor reflex. RPP also increase gradually with the


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number of reps since the myocardial consumption follows this same pattern. They can

reach extremely high levels because of the tachycardia and exaggerated SBP response.

Chapter 3:

1. The first step of carbohydrate metabolism is glycolysis. Glycolysis consists of a series of

10 or 11 steps. It occurs in the cytoplasm of cells and is anaerobic. Glycolysis begins with

glucose or glycogen and end with pyruvate or lactate. It is the energy pathway

responsible for the initial catabolism of glucose. ATP is produced during this first step of

glycolysis and this is the only way to produce ATP in the absence of oxygen. The second

step of carbohydrate metabolism is the formation of acetyl coenzyme A. This stage

results in the formation of acetyl coenzyme A from pyruvate. Although no oxygen is

directly used, the process is aerobic. No ATP is produced or used directly. The third step

of carbohydrate metabolism is the Krebs cycle. This stage consists of eight steps and

occurs in the mitochondrial matrix. No oxygen is used again but the process must be

aerobic. Two ATP are produced by substrate-level phosphorylation from ADP and P and

CO2 is formed. H atoms are removed and carried by NAD and FAD to the electron


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transport system. The fourth step of carbohydrate metabolism is electron transport and

oxidative phosphorylation. Electron transport takes place in the inner mitochondrial

membrane and consists of relaying electrons from the hydrogen atoms from one protein

carrier to another and transporting the remaining hydrogen ions into the intermembrane

space. An electrical current is created in the process and this energy is used to synthesize

ATP from ADP by the addition of a phosphate as the H move through the ball-and-stalk

apparatus into the mitochondrial matrix. For each hydrogen carried to the electron

transport system by NAD, 3 ATP are formed. For each hydrogen carried by FAD to the

electron transport chain, 2 ATP are formed.

2. 2 ATP (substrate-level phosphorylation, glycolysis) + 4 ATP (NADH + H+ FADH2,

glycolysis) + 6 ATP (NADH + H+, Stage II) + 2 ATP (substrate-level phosphorylation,

Krebs Cycle) + 22 ATP (FADH2 + NADH +H, Krebs cycle ETS/OP) = 36 ATP for the

aerobic oxidation of one molecule of glucose by skeletal muscle. A total of 37 ATP are

produced if the fuel substrate is glycogen and the muscle is skeletal. A total of 38 ATP

are produced if the fuel substrate is glucose and the muscle is cardiac. A total of 39 ATP

are produced if the fuel is glycogen and the muscle is cardiac.

3. The number of ATP produced from the breakdown of fat depends on which fatty acid is

utilized. n/2-1 describes the number of cycles. The number of ATP produced from the

breakdown of fat depends on which fatty acid is utilized. n/2 1 = number of cycles.

Each cycle produces 1 FADH2 (2 ATP) and 1 NADH + H+ (3 ATP). Add 2 ATP and 3ATP together and then multiply this number by the number of cycles. Each cycle plus the

last step produces acetyl CoA. Each acetyl CoA yields 1 ATP, 3 NADH + H+ (9 ATP)

and 1 FADH2 (2 ATP) in the Krebs cycle, for a total of 12 ATP for each acetyl CoA.


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Add the results of steps 2 and 3. Subtract 2 ATP from this result since 2 ATP were

utilized in step 1 of beta oxidation to achieve the fatty acid. 24/2-1 = 11 cycles. FADH2 +

NADH + H+ = 5 ATP. 5x11 = 55 ATP. 12 acetyl CoA x 12 ATP = 144 ATP. 55 ATP +

144 ATP 2 ATP = 197 ATP.

4. Before amino acids can be used as a fuel and enter the pathways at any place, the NH2

must be removed. This is accomplished through the process of transamination.

Transamination involves the transfer of the NH2 amino group from an amino acid to a

keto acid. This process occurs in the cytoplasm and mitochondria in mostly muscle and

liver cells. It results in the formation of a new amino acid and a different keto acid. Inoxidative deamination, the oxidized form of NAD is reduced and the amino group is

removed and becomes NH3.

5. Acetyl coenzyme A is called the universal common intermediate because it is the

common intermediate by which all foodstuffs enter the Krebs cycle and electron transport

system.

6. When carbohydrates are inadequate, oxaloacetate is converted to glucose. The production

of glucose from noncarbohydrate sources under these conditions is necessary because

some tissue rely predominantly on glucose as a fuel. When oxaloacetate is converted to

glucose and is not available to combine with acetyl CoA to form citrate, the liver converts

the acetyl CoA derived from the fatty acids into metabolites called ketones or ketone

bodies. Ketones have three forms which are acetoacetic acid, beta-hydroxybutyric acid,

and acetone. Acetone gives the breath a very characteristic fruity smell. If the ketones are

not used but, instead, accumulate, ketosis occurs which can disrupt normal physiological


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functions due to its high acidity. Ketosis usually occurs from inadequate diets such as in

the condition anorexia nervosa.

7. At rest, it has been estimated that fats contribute from 41-67%, carbs contribute from 33-

42%, and proteins contribute from just a trace to 17% of the total daily energy

requirements of the human body. During exercise various forms of each fuel are utilized

to supply the working muscle with the additional ATP energy needed to sustain

movement. Very short duration, very high intensity dynamic activity and static

contractions are special cases that rely predominantly on energy substrates stored in the

muscle fibers, namely ATP-PC and glycogen. Generally, the lower the intensity, the moreimportant fat is as a fuel; the higher the intensity, the more important carbs are as a fuel.

Duration has a similar effect in that the shorter the duration, the more important carbs are

as a fuel, with fat being used more and more as the duration extends. Fats come into play

over the long term because the glycogen stores can and will be depleted. Long-duration

activity exhibits a three-part sequence in which muscle glycogen, bloodborne glycogen,

and fatty acids predominate as the major fuel source. Protein may account for 5-15% of

the total energy supply in activities lasting more than a hour.

Chapter 4:

1. The energy continuum begins with the production of ATP which can be stored in the

muscle. Another high-energy compound called phosphocreatine can be used to

resynthesize ATP from ADP instantaneously. The amount of PC in muscle is about three

times that of ATP. Muscles differ in the amount of stored PC by fiber type. Fibers that

produce energy predominantly by anaerobic glycolysis are called glycolytic and those

that produce energy predominantly aerobically are called oxidative. Anytime the energy


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demand is increased at least part of the immediate need for the energy is supplied by

these stored forms, which must eventually be replenished. Together, the ATP-PC supply

can support slightly less than 10 seconds of maximal activity. This ATP-PC system

neither uses oxygen nor produces lactic acid and is said to be alactic anaerobic. When the

demands for ATP exceed the capacity of the phosphagen system and the aerobic system,

anaerobic glycolysis is utilized. Because this system does not involve the utilization of

oxygen but does result in the production of lactic acid, it is aid to be lactic anaerobic. The

generation of ATP from aerobic glycolysis, the Krebs cycle, and electron transport-

oxidative phosphorylation is constantly in operation at some level. Under restingconditions, the aerobic oxidation step provides all of the energy needed. When activity

begins, oxidation increases quickly in order to supply the necessary amount of ATP.

These three sources of ATP are recruited in a specific sequence called the time-energy

system continuum. This continuum assumes that the individual is working at a maximal

maintainable intensity for a continuous duration. All three systems (ATP-PC, LA, O2)

are involved in providing energy for all durations of exercise. The ATP-PC system

predominates in activities lasting 10 sec or less and still contributes at least 8% of the

energy supply for maximal activities up to 2 min in length. As the duration lengthens, it

becomes a smaller portion of the total energy supply. Anaerobic metabolism (ATP-PC

and LA) predominates in supplying energy for exercises lasting less than 2 minutes. The

longer the duration, the greater the relative importance of the lactic acid system is in

comparison to the phosphagen system. By 5 min of exercise, the O2 system is clearly the

dominant system. The longer the duration, the more important it becomes.

a. 100-m dash: 76% ATP-PC, 12% LA, 12% O2


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The system with the highest amount of power is ATP-PC (72 kcal/min), then the LA

system (36 kcal/min) and lastly the O2 system (9 kcal/min). Capacity is exactly the

reverse of power. The O2 system is the highest in capacity with the ability to sustain

exercise for more than 2 hours, then the LA system which can sustain exercise for almost

1 hour and 20 min, and finally the ATP-PC system which only can sustain exercise for 9-

10 seconds.

4. The original concept of an anaerobic threshold is based upon the lactate

response to incremental exercise and the relationship of the lactate

response to minute ventilation. It is a coincidence that theventilatory and lactate thresholds often occur at approximately the

same time since ventilation and lactate appear to exhibit two

distinct breakpoints as they rise. The anaerobic threshold is defined

as the exercise intensity, usually described as a percentage of

VO2max or workload, above which blood lactate levels rise and

minute ventilation increases disproportionately in relation to

oxygen consumption. The onset of anaerobic metabolism, which is assumed to lead to the

lactate accumulation, is attributed to the failure of the cardiovascular system to supply the

oxygen required to the muscle tissue. The disproportionate rise in ventilation is attributed

to the excess CO2 resulting from the buffering of the lactic acid.

5. The physiological effects of lactate accumulation are extreme pain and

discomfort along with a large decrease in muscle performance level.

6. During exercise, blood and lactate levels escalate and blood levels

continue to rise even after exercise. Lactate is removed from the bloodstream relatively


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rapidly following exercise. Removal does not occur at a constant rate and appears to be

one of those substrates whose utilization and conversion is linked with the amount of

substrate present. In a resting recovery situation, half of the lactate is removed in about

15-25 min no matter what the starting level is. Near-resting levels are achieved in about

30-60 min. The initial postexercise concentration of lactate is the first factor that

influences the rate of removal; the higher the concentration, the faster the rate of removal.

The best way to clear lactate quickly during recovery is when an individual exercises

during recovery than when they rest by sitting quietly.

7. The total genetic effect on the alactic anaerobic capacity was estimatedto be between 44% and 76%. There is some degree of genetic influence on anaerobic

characteristics but the exact amount is unknown. At least to a certain extent, sprinters are

born.

Chapter 5:

1. The two variables to describe the aerobic metabolic response to

exercise are oxygen consumption and carbon dioxide production. Oxygen consumption

or VO2 is the amount of oxygen taken up, transported, and used at the cellular level. It

equals the amount of oxygen inspired minus the amount of oxygen expired. Carbon

dioxide produced or VCO2 is the amount of carbon dioxide generated during

metabolism, primarily from aerobic cellular respiration. It equals the amount of CO2

expired minus the amount of CO2 inspired. Open-circuit indirect spirometry is a fine way

to measure oxygen consumption during physical activity but due to the inconvenience of

the equipment required, the most popular exercise-testing modalities in the laboratory are

the motor-driven treadmill and the cycle ergometer. Laboratories use a computer


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programmed with software to find carbon dioxide production. They plug the values from

treadmill tests and other equipment tests to find the aerobic metabolic responses during

exercise. VCO2 is found by multiplying the volume of air expired by the percentage of

CO2 in the expired air subtracted by the volume of air inspired by the percentage of CO2

in the inspired air.

2. a. short term, light to

moderate

b.

long term, moderate to heavy sub-maximal

c. incremental exercise to maximum

3. The value of oxygen going to support the respiratory muscles does not

remain constant but varies with the intensity of activity. During rest the respiratory


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caloric cost with both of these values. They can be used as a rough guide for determining

how long work can be sustained at each intensity.

5. Gross efficiency is the simplest calculation which involves the work

output divided by the energy expended multiplied by 100. It is most useful when values

for specific workloads, speeds, or the like, are of interest. Gross efficiency also is

important for applications in nutritional studies where gross energy expenditure is a

matter of concern for adequate replenishment. It is the measure that has been reported

most frequently. Net efficiency is a slightly more complex method where the energy

expended is corrected for resting metabolic rate. Net efficiency is the work output divided by the energy expended minus the resting metabolic rate for the same time period

multiplied by 100. Net efficiency is a better indication of the efficiency of work per sec.

Despite this, it is not a particularly realistic value, since an individual performing any

external work is still expending resting energy. Delta efficiency requires the use of two

workloads and is based on the difference between the two loads. It is found by dividing

the difference in work output between two loads by the difference in energy expenditure

between the same two loads multiplied by 100. The most accurate means for determining

the effect of speed or work rate on efficiency is the use of delta efficiency. It gives an

indication of the relative energy cost of performing an additional increment of work.

Delta efficiency is also the technique of choice when calculation efficiency on treadmill.

Cyclists can maximize their efficiency by finding the optimal seat height, optimizing the

pedal frequency, and keeping the revolutions per minute constant.

6. Both efficiency and economy are important factors in optimizing an

individuals performance during exercise. Even though the amount of physical work


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completed in an exercise modality is the same amount of work accomplished in the same,

or different, exercise modality, the same metabolic effect may not be experienced. The

deciding factor of each exercise comes down to the energy cost of the activity.

Chapter 8:

1. Densitometry is the measurement of mass per unit of volume.

Hydrostatic weighing determines body composition through the calculation of body

density and the purpose of densitometry is to divide the body into the compartments of

fat and fat-free weight.

2. The densities of the fat and fat-free weight are known and additive. Thedensities of water, none mineral, and protein that make up the fat-free weight are known

and relatively constant form individual to individual. The percentage of each fat-free

component is relatively stable from individual to individual. The individual being

evaluated differs from the assumptions of the equation being used only in the amount of

storage fat. For children and adolescents, the percentage of water is higher and the

percentage of mineral content is lower than in a normal adult. Since the components are

constantly changing as children mature, no single formula can be used for children of

different ages. The use of equations developed with the assumption of the composition of

adult components will overestimate the %BF of the child or adolescent. For the elderly,

consideration needs to be given to the effect of the loss of bone mineral density on the

determination of %BF. A loss of bone mineral density would cause a decrease in body

density and an overestimation of %BF if it were not accounted for. Normal adults can

very readily be hydrostatically weighed to find out their %BF and then can change their

lifestyle and habits to improve their %BF. If a 9-year-old girl is hydrostatically weighed,


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the %BF found from the general Brozek formula would be a large overestimation

compared to the Lohman age and sex-specific formula.

3. Strengths are excess weight can actually be caused by high levels of

lean muscle mass, but additional muscle mass is beneficial. Excess fat is only beneficial

for swimmers in cold water who need extra fat for protection. The weaknesses of being

overweight are it makes the individual very unhealthy with problems such as weaker

muscles and bones, more energy is required to perform different actions, the heart has a

greater stress placed on it, there is a greater risk for diabetes, etc. Obesity is just like

being overweight except the weaknesses are amplified and there are absolutely nostrengths. I would use bioelectrical impedance in a field setting because it is the easiest

method to use without having access to hydrostatic weighing and the values are much

more consistent than skinfold results which must be precisely done to be accurate.

4. The margin of error in skinfold tests are within 3-5% compared with

underwater weighing unless improper techniques are used which result in much larger

errors. Bioelectrical impedance tests are just as accurate as skinfold tests when done

correctly and can be anywhere from 3-5% error compared to underwater testing.

Hydrostatic weighing is extremely accurate within 1% accuracy of the true %BF of the

individual.

5. Prior to puberty, there is very little sex difference in %BF. After puberty

male values drop until approximately 30 years of age and then rise; female values rise

slowly and then tend to jump. By age 30 both male and female averages fall in the

overweight category and by age 50 both male and female averages fall in the obesity

category. Overweight and obesity values for males tend to be much lower than female


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values. Also, males have much lower %BF values than females. This is because adult

females have approximately 50% more fat cells than adult males and during puberty, fat

cell size increases in females but not in males. Most males exhibit the android pattern of

fat distribution which is known as the abdominal or apple pattern. It is characterized by

the storage of fat in the nape of the neck, shoulders, and abdomen. The largest quantity of

fat is stored internally, not subcutaneously. The fat tends to feel hard upon feeling. Most

females exhibit the gynoid pattern which is also called the gluteofemoral or pear pattern.

It is characterized by the storage of fat in the lower part of the body, in the thighs and

buttocks, with the largest quantity being stored subcutaneously. The fat tends to be softand jiggle upon feeling. The third type of fat distribution is the intermediate pattern

which is common in both males and females.

6. People with a BMI between 25 and 29.9 are sometimes designated as

overweight for adults and a BMI over 30 is considered to be in the obesity range.

7. Adipocytes can chance in size about tenfold if needed to store

triglycerides. This increase in size is the way in which increasing levels of fat are first

stored. Sometimes when the fat cell size is enlarged, the increased size cause a bulging

between the fibrous tissue strands, causing a dimply, waffled appearance. These lumpy

areas are known as cellulite. Once the upper limit of fat storage by hypertrophy is

approached, fat cell hyperplasia occurs which is growth in a tissue or organ through an

increase in the number of cells. A newly overweight adult is likely to have the same

number of fat cells as when they were of normal weight, but these adipocytes will be

larger than before. An obese person may have enlarged adipocytes, an increased number

of adipocytes, or both. Obese individuals may have as many as 75-80 billion fat cells.


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Chapter 19:

1. The largest major component of the whole muscle is the epimysium,

then the tendon, perimysium, fasciculi, endomysium, and finally the smallest component

is the muscle fiber.

2. The repeating pattern of the myofilaments along the length of the

myofibril gives skeletal muscle its striated appearance.

3. I bands contain only thin filaments. A bands contain thick and thin

filaments, with the thick filaments running the entire length of the A band. The H zone

lacks an overlap of thick and thin filaments. The dense M line runs through the center of the H zone. The Z disc serves to anchor the thin filaments to adjacent sarcomeres.

4.

5. The role of ATP is very essential in steps 3 and 4 of the cross-bridge

cycle. It is the binding of ATP molecules to the myosin head, in step 3, that allows the

myosin heads to detach from actin. In the fourth step it is the breakdown of ATP that

provides the energy to activate the myosin heads. ATP binding to the myosin head is

necessary to break the cross-bridge linkage between the myosin heads and the actin so


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that the cycle can be repeated. ATP is also used for the return of calcium into the

sarcoplasmic reticulum and restoration of the resting membrane potential once

contraction has ended.

6. When calcium is released from the sarcoplasmic reticulum, it binds to

the troponin molecules on the thin filament. The binding of calcium to troponin cause

troponin to undergo a configurational change, thereby removing tropomyosin from its

blocking position on the actin filament.

7. When a motor neuron is stimulated, all of the muscle fibers in that

motor unit contract to their fullest extent or they do not contract at all. The minimalamount of stimuli necessary to initiate that contraction is referred to as the threshold

stimulus; that is, if the threshold of contraction is reached, a muscle fiber will contract to

its fullest extent.

8.

ForceProduction

FatigueCurve

TwitchSpeed


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9. Available evidence indicates that the distribution of fiber types based

on contractile properties is genetically determined and is not altered in humans by

exercise training. Training can alter the metabolic properties of the cell which may lead

to the conversion of FT fiber subdivisions. Basically, fiber type distribution is primarily

genetically determined and can not be influenced by exercise training.

Chapter 20:

1. Bending the knees would definitely not eliminate the involvement of

thigh muscles if the feet are held down. If the feet are held, abdominal muscles are moreactive.

2. The angle of knee bend affects the abdominal muscle group the most,

specifically the external obliques.

3. The feet should not be held to maximize the involvement of the

abdominal muscles.

4. I would recommend that the feet are not held and the knee angle is

between 100 and 130 degrees to let the knees be relaxed

without causing pain to the joint.

5. Within a muscle fiber, the amount of

muscle tension that can be exerted is related to the

initial length of the sarcomeres. The amount of tension

produced is directly related to the overlap of the thick

and thin filaments. In shortened fibers, where the thick and

thin filaments already almost completely overlap, there is


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little room for further shortening. Less force is produced in both the elongated and

shortened positions as a result. The maximum number of cross-bridges coincides with the

highest force production. In whole muscle, this length-tension relationship hold, but its

expression is complicated by many factors such as the cross-sectional area of the muscle,

the arrangement of the sarcomere to the line of pull, the level of neural muscle activation,

the degree of fatigue, the involvement of elastic components of muscle, and the

biomechanical aspects of how a muscle exerts force at a joint. Whole muscle tension

plotted against the joint angle at which it occurs generates strength curves.

Strength curve for:

Bicep flexion Knee

flexion Knee extension

6. An eccentric

contraction occurs where the force curve

dips below the horizontal axis.

Whole Muscle


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A static contraction occurs at zero velocity and maximal load.

7. The mechanical trauma theory implies that the mechanical forces in the

contractile or elastic tissue result in structural damage to the muscle fibers. Damage to the

sarcolemma of the cell leads to disruption in calcium homeostasis, which results in

necrosis. The presence of cellular debris and immune cells leads to swelling andinflammation, which is responsible for the sensation of DOMS. On the other hand, the

local ischemic model suggests that exercise, even moderate, atraumatic activities, causes

swelling in the muscle tissue, which increases tissue pressure. This increase in tissue

pressure is thought to result in local ischemia (reduced blood flow), which causes pain

and leads to tonic muscle constriction. This spasm causes additional swelling and

perpetuates a cycle of swelling and ischemia that results in the painful sensation known

as DOMS. The main difference in the models is the fact that in the local ischemic model,

overuse initiates the sequence while in the mechanical trauma model, high mechanical

forces in contractile element initiates the sequence. The local ischemic centers on the idea

that overexertion involving long-duration and moderate-intensity activities leads to

DOMS. The mechanical trauma model concentrates on the manifestation of DOMS after

activities that place considerable mechanical force on the muscle, specifically, eccentric

contractions that cause DOMS. Both theories could be correct because there is a


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Chapter 22:

1. All human movement depends on the nervous system; skeletal muscles

will not contract unless they receive a signal from the nervous system. All skeletal

muscles require nervous stimulation to produce the electrical excitation in the muscle

cells that lead to contraction.

2. An AP in the axon

terminal causes the uptake of Ca+2 into

the axon terminal and the subsequent

release of the neurotransmitter. The Achis released and diffuses across the

synaptic cleft. Generation of action

potential: The binding of Ach to

receptors on the sarcolemma causes a

change in membrane permeability. The

AP is propagated into the interior of the cells via the T tubules.

3. The receptor is the organ that

responds to the stimulus by converting it into a

neural signal. The afferent (sensory) neuron

carries the signal to the central nervous system

(CNS). The integration center is in the CNS and is

where the incoming neural signal is processed

through the connection of the afferent neuron with

association neurons and efferent neurons. The efferent (motor) neuron carries the impulse


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from the CNS to the organ of the body that is to respond to the original stimulus. The

effector organ is the organ of the body that responds to the original stimulus.

4. The myotatic reflex begins with a response to a sudden change in length

of the muscle. When a muscle is quickly stretched, the annulospiral nerve ending in the

NMS sends an impulse to the spinal cord. This results in an immediate strong reflex

contraction of the same muscle from which the signal began.

5. In volitional control of movement, the frontal lobe makes the decision

and initiates movement. Then the signal is transmitted down the appropriate descending

tract. The efferent motor neuron then carries the impulse to the muscle, the effector

organ. Upon receiving the signal from the nervous system, the muscle contracts and

produces movement. Changes in muscle length, tension, and position stimulate receptors

in the muscles and joints of surrounding muscles. This information is transmitted to thecentral nervous system through afferent sensory neurons. In some instances the neurons

synapse with association neurons, which synapse with efferent motor neurons to


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reflexively control movement. In other cases, the association neurons synapse with

neurons of the ascending tract, which will carry information to the brain.

6. Flexibility and stretching are important for everyday living, for muscle

relaxation and proper posture, and for relief of muscle soreness. A flexibility-training

program is used as a preparation for activity which will enhance the performance of that

activity and as a means of decreasing the likelihood of injury during physical activity.

There is no doubt that flexibility is important to sport performance. Flexibility helps

decrease the chance of injuries and allows a greater range of motion during exercise.

7. Static stretching is a form of stretching in which the muscle to bestretched is slowly put into a position of controlled maximal or near-maximal stetch. The

position is then held for 30-60 seconds. Since the rate of change in muscle length is slow

as the individual gets into position and then is nonexistent as the position is held, the

annulospiral nerve endings of the neuromuscular spindle are not stimulated to fire and a

strong reflex contraction does not occur.

8. PNF is a stretching technique in which the muscle to be stretched is first

contracted maximally. Then the muscle is relaxed and is either actively stretched by

contraction of the opposing muscle or is passively stretched. Since the rate of change of

the muscular length is slow as the individual approaches the maximal stretch position, the

annulospiral nerve endings of the NMS are not active to fire and no reflex contraction

occurs.

9. Flexibility is joint specific and is also task or sport specific. Thus, the

first step in developing a flexibility program is to analyze the task or sport to determine

the degree of flexibility needed, the specific joint(s) involved, and the plane of action


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involved. Overload in flexibility training is achieved by placing the muscle and

connective tissue at or near the normal limits of extensibility and manipulating the NMS

and GTO by holding the position or contracting the muscle to achieve an elongation.

Since the individual begins both static and PNF stretching exercises at the limit of

extensibility, progression will naturally follow whatever adaptation does occur. The most

important consideration in flexibility training is that the goals and technique preferences

of the individual be considered. Once the appropriate or desired level of flexibility has

been attained, it can be maintained by just one day per week of training at the same

intensity level. There will be a point in a flexibility training program when further improvement ceases. Lastly, there should be a cardiovascular warm-up to elevate the

body temperature preceding the flexibility exercises regardless of the reason for

stretching.

honors exercise physiology manuscript

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