Workbook 1 Flashcards
An individual bout of exercise; the bodies immediate response to an exercise bout
acute exercise
What is the primary function of the cardiovascular system?
ensure adequate blood flow throughout circulation to meet the metabolic demands of the tissues
which nervous system controls HR ?
sympathetic
two formulas for determining HR max? Which is most accurate?
- 220 - age
2. 208 x ( .7 x age in years ) * more accurate
Steady state HR
- 2-3 minutes to reach at constant intensity
- the demands of the active tissues can be adequately met by the cardiovascular system
systolic blood pressure _____ during acute exercise. What about diastolic?
increases
- diastolic does not change significantly during exercise (may slightly decrease)
Receptors are responsible for what?
What are the 3 receptors?
- modifying blood pressure
1. baroreceptors
2. chemoreceptors
3. mechanoreceptors
What do each of the 3 receptors do?
- Baro: excited by stretch of vessel, alert brain
- Mechano: golgi tendon, stretch receptors
- Chemo: monitor O2 levels; chem. of blood
What is stroke volume?
Volume of blood pumped out of LEFT ventricle per contraction
SV = ___ - ____ ?
EDV - ESV (ml)
what is the major determinate of cardiorespiratory endurance capacity (VO2max) ?
stroke volume
4 factors that determine stroke volume
- volume of venous blood returned to heart [preload]
- ventricular dispensability
- ventricular contractility
- aortic or pulmonary artery pressure [afterload]
Stroke volume increases proportional to ___ ____
work rate (plateaus ~40-60% of VO2max)
End diastolic volume (EDV) is..
amount of blood before contraction
End systolic volume (ESV) is..
amount of blood left after contraction
epinephrine increase _____ force
contraction
why is stroke volume influenced by body position?
venous return to the heart; horizontal position has higher stroke volume because of gravity
stroke volume increases with acute exercise for what 3 reasons
- frank-starling mechanism
- sympathetic stimulation
- decreased peripheral resistance due to increased vasodilation to active muscles
what is the frank-starling mechanism?
- Increased volume of blood enters the ventricle (EDV)
- Ventricle stretches and
- Contracts with more force
what is cardiac output?
total volume of blood pumped by the LEFT ventricle per minute
Q (cardiac output) = __ x __
HR x SV (L/min)
Average resting Q ?
5L/min
total blood volume of typical adult is ~5L
Q increases with exercise intensity up to….
~ 20-40 L/min
8x more than resting value
3 functions of blood flow that are important for exercise
- transport oxygen
- temperature regulation
- acid-base balance
redistribution of blood flow is caused by the ______ response
sympathetic
3 parts of blood flow redistribution
- Blood flow into exercise muscles increases from 15-20% Q to 70-85 %Q
- Blood flow into the skin increases 5x resting values
- Blood flow to digestive system decreases from ~25% Q to 5% Q
_______ transport oxygen
hemoglobin
blood acidity ____ during exercise
increase [bicarbonate -baking soda- buffers acidity]
single best measurement of cardiorespiratory endurance and aerobic fitness?
VO2max
what is VO2 max?
rate of O2 and CO2 exchanged in the lungs;
rate of use & release by the body tissues
During submax exercise at a constant power output, VO2max increases from its resting value to a steady state value within …
2-3 minutes
During submit exercise increases in metabolism and VO2 are proportional with increases in…
work rate [exercise intensity]
During max exercise, VO2 max represents the max capacity for _____ _____ by the body during max exertion
oxygen consumption
VO2 max is expressed relative to what ? what are the units?
body weight
units: ml/kg/min
When does VO2max decline?
after age 25-30 by 1% per year
______ volume increases with increasing intensity of exercise
tidal
at _______ workloads, ventilation rate plateaus once steady state is achieved
constant
At _______ workloads, ventilation rate increases proportionally to work load until athlete reaches ventilatory threshold
increasing
what is tidal volume?
amount of air going in and out during regular breathing
what is ventilatory threshold?
when ventilation rate rises exponentially with increasing exercise workload/intensity because the body shifts from aerobic to anaerobic state
there is a spike in ______ rate at anaerobic state
respiration
Resting heart rate decreases ~1 bpm with each week of training. Why ?
- Increased parasympathetic (vagal) tone
[[parasympathetic tone holds resting heart rate down to about 70-80 bpm; calming effect]] - Increased stroke volume [amount of blood ejected by left ventricle]
What is submaximal HR ?
decreased HR for a given absolute exercise intensity (any intensity below max)
does max HR change as the body adapts to endurance training?
No - it is based on age and cannot change
How long do adaptations to aerobic exercise take normally
4-6 weeks
what is heart rate recovery?
time it takes the heart to return to its resting state after exercise
what increases the rate of recovery in HR ?
training
Recovery HR is a(n) _______ measurement of cardio fitness
indirect
HR recovery is prolonged by certain environments including:
heat, altitude
blood flow to active muscles is increased by an increase in what 4 things?
- capillarization and recruitment (body creates more to adapt)
- effective redistribution
- blood and plasma volume
- RBC volume and hemoglobin
blood viscosity decreases due to what ? What is the result?
increase in plasma volume (more water); improves blood flow and O2 delivery
Systolic BP reduces at ____ as well as during _____ exercise, but increases with _____ exercises as the heart is now stronger and able to generate greater pressure
rest; submaximal; maximal
BP decreases due to a decrease in ____ _____
blood viscosity
Chronic adaptations to aerobic exercise and the effects on oxygen transport
- increased EPO produced
- EPO stimulates RBC production
- RBC’s increase O2 transport
EPO is released by …
the kidneys HOLLA
what is the #1 factor affecting VO2?
Genetics
what is ventilation?
movement of air between the environment and the lungs via inhalation and exhalation
chronic adaptations to aerobic exercise result in what changes for ventilation?
- little change at rest
- Increase pulmonary ventilation during max exercise
- strengthens primary and accessory respiratory muscles
an increase in pulmonary ventilation during max exercise is a result of what 2 things
- increased tidal volume
2. increase respiratory rate
what is the valsalva maneuver ?
breathing technique where air is trapped in the lungs against a closed glottis, increasing abdominal pressure
what does the valsalva maneuver result in ?
- decreased venous return
- Increased pressure in chest cavity
- Dizziness and fainting
are blood pressure responses greater during the concentric phase or eccentric phase?
concentric (shortening of muscle)
what is orthostatic hypotension?
aka postural hypotension
- decrease in blood pressure when standing up
nutrients from foods are the substrates for metabolism and are provided/stored as:
carbohydrates, fats, proteins
the energy we derive from food is stored in the cells in the form of what
ATP (adenosine triphosphate)
immediate source of energy for most body function including muscle contraction:
ATP
ATP is generated through 3 energy systems. What are they?
- ATP-PCr system
- Glycolytic system
- Oxidative system
Explain the ATP-PCr system
- cells store small amounts of ATP and phosphocreatine (PCr) which is broken down to regenerate ATP
- release of ATP from PCr is done by enzyme creatine kinase
- anaerobic process (no oxygen required)
- ATP-PCr supply muscle energy needs for 3-15 sec during sprint
Explain the Glycolytic system
10 to 12 enzymatic reactions break down glycogen into lactic acid, producing ATP
- anaerobic process
ATP-PCr and the glycolytic system combined provide the energy for
2 minutes of all-out activity
In anaerobic systems:
1 mole of glycogen produces ___ moles ATP.
1 mole of glucose produces ___ moles ATP.
- 3 moles
- 2 moles
Describe the oxidative system
- uses oxygen to generate ATP (aerobic)
- production occurs in mitochondria
- Produces more ATP than anaerobic systems
- Slow to turn on (2-3 min.)
- primary method of energy production in endurance events
- Includes Krebs cycle and ETC
In aerobic system:
1 molecule glycogen can generate _____ molecules of ATP
37-39 molecules
Krebs and ETC combined
what system provides ATP for an 800 m sprint?
glycolytic (2 min exercise)
what is the RER ?
- respiratory exchange ratio
- ratio between CO2 released (VCO2) and oxygen consumed (VO2)
What is the equation for determining RER?
RER = VCO2 / VO2
What does the RER reveal?
what primary substrate our body is using for energy production
RER at rest = ____
RER oxidation of fat = _____
RER oxidation of carbohydrate = ______
- 80 (70% fat, 30% carb usage)
- 70
- 0
energy expenditure is expressed in what 3 ways
- METs (metabolic equivalent)
- VO2
- Kilocalories
amount of energy expended during 1 minute of seated rest
1 MET
1 MET = VO2 of ____ ml O2/kg/min
3.5
1 MET = ____ kcal/min for a 70 kg individual
1.2
skeletal muscles are _____, controlled by the _____ nervous system
voluntary
somatic
the sarcomere of a muscle contains the ______ elements between each pair of _____
contractile; z-disks
ends of these muscles pull toward each other in the Y direction
longitudinal/parallel muscles
biceps femoris, brachii, sartorius
these types of muscles pull in the x and y directions
pennate muscles (rectus femoris, deltoid)
the greater the angle of pennation, the _____ force produced by the muscle
less
in pennate muscles there are more ______ so angle of pennation may not make a difference in force production
fibers/area
Slow twitch (TYPE 1) muscle fibers
- efficient at using oxygen to generate ATP for continuous, extended muscle contractions over a long time
- fire slower than fast twitch and can go for a long time before they fatigue
- great for marathons and cycling for hours
Fast Twitch (TYPE 2) muscle fibers
- Use anaerobic metabolism to create fuel
- Better at generating short bursts of strength/speed
- Fatigue more quickly
- Produce the same amount of force but get their name because they fire more rapidly
- Asset to a sprinter [quickly generate a lot of force]
3 types of type 2 fast twitch fibers
type IIa - fast oxidative/glycolytic (FOG)
type IIx - fast glycolytic (FG) (lifting)*
type Iic - limited information/unknown
percentage of each of the 3 types of fast twitch fibers depends on what ?
muscles, individuals, training
proportion of type I and type II fibers in a persons arm and leg muscles are usually similar
true
type 1 vs. type 2a
type 1: long runs
type 2a: shorter runs
what is the SAID principle?
Specific
Adaptations to
Imposed
Demands
Early gains in strength appear to be influenced by _____ factors
neural
Long term gains are largely the result of _______
hypertrophy
what is hypertrophy?
net increase in muscle protein synthesis (increase in size of fiber)
strength gains are facilitated by…
post-exercise nutrition (protein)
testosterone plays a role in promoting _____ ______
muscle growth
acute muscle soreness
occurs immediately after exercise
accumulation of end products in muscles (edema)
disappears minutes/hours after exercise
DOMS [delayed onset muscle soreness]
soreness felt 12-48 hrs after exercise
primarily from eccentric muscle activity (downhill running, eccentric weight training) but can be caused from concentric
6 causes of muscle fatigue
- energy depletion (3 systems, diet)
- Accumulation of H+ which decreases pH
- Failure of muscle fiber contractile mechanism
- Muscle fiber type
- Alterations in nervous system
- Fitness level
explain the accumulation of hydrogen and decrease of pH
cell produce H+ which increases acidity (below 6.4 pH. muscles shut down to shut down mitochondria because of increased acidity)
intrinsic properties of cardiac muscle
- contain intercalated disks (assist in rapid transport of action potentials)
- heart conduction system: SA Node -> AV node -> AV bundle (bundle of his) -> Purkinje fibers
- the SA node is the bodies natural pacemaker
extrinsic properties of cardiac muscle
- chronotropic effect [autonomic nervous system]
- inotropic effect [strength of contraction; influence of frank-starling mechanism]
organic component of bone:
35% collagen, slightly flexible
inorganic component of bone:
65% calcium phosphate, hard
2 types of bone tissue
- compact [cortical] 80% of body’s bone; hard, dense
2. Spongy [cancellous] 20% of the body’s bone [end of bone]
Explain longitudinal growth of bone
- takes place at epiphyseal plates (epiphysis at end of bone)
- plates produce new cells on disphyseal side of bone ages 18-25
explain circumferential growth of bone
internal layers of periosteum lay down concentric layers of bone [cells: osteon]
what is bone resorption?
occurs around medullary cavity; osteoclasts resorb bone osteoblasts make new bone
*density decreases with age because decrease in osteoblasts and increase in osteoclasts
what is wolf’s law ?
a bone grows or remodels in response to forces or demands placed upon it
Basic internal mechanics suggest that the body is like a lever-polly-fulcrum system. How so ?
Bones: levers
Muscle: pulley
joint: fulcrum
*1st, 2nd, 3rd class lever arrangement
First class levers in the body
- E __ F __ L (see-saw)
- best for balance
- triceps, occipito-atlanto joint (head balance on spine)
Second class levers in the body
- F ____ L ____ E
- best for power
- foot during plantarflexion
Third class levers in the body
- F ___ E ___ L
- best for ROM
- most joints in the body
force = ?
mass x acceleration
Newtons 3 laws
- Law of inertia: movement will not change without opposition (no force, no movement)
- Law of acceleration
- Law of action-reaction: any force creates an equal and opposite counter force; GRF (ground reaction force)
explain newtons 2nd law of motion:
Law of acceleration
- force is positively related to acceleration and mass
- acceleration is proportional to force and inversely proportional to mass
- acceleration is the rate of change of velocity
* faster velocity = more force
forces affecting movement when walking, jogging, and sprinting
walking: 1.5x body weight
jogging: 2x body weight
sprinting: 2.5x body weight
explain GRF
ground reaction force
- Force exerted by the ground on a body in contact with it. (equal and opposite counter force)
friction is proportional to what?
the force pushing two surfaces together
what mostly affects friction force?
type of surface of the object (rough vs smooth)
what is greater, static or dynamic friction?
static friction (force which sets object in motion, dynamic keeps it going)
this occurs when greater forces are generated at slower velocities
contraction velocity (force-velocity relationship)
Which contractions produce greater forces, eccentric or concentric ?
eccentric (lengthening)
the muscle tendon produces the most force at what angle of insertion into the bone?
90 degrees
there is an inverse relationship between force and velocity. what does this mean?
increase in force results in decrease in velocity
the ability to control one’s equilibrium
balance
resistance to movement
stability
6 ways to improve stability (resistance to movement)
- increase body mass
- increase friction
- increase size of support base
- COG near edge of support base toward oncoming force
- COG in middle of support base if not force
- COG low as possible
COM vs COG ?
COM = base of support; body’s mass is equally distributed
COG = balance point; where force of gravity acts on body
**often treated as same point
Components of the stance phase
60% of gait cycle
- Initial contact
- Mid-stance
- Late-stance (active propulsion)
- Pre-swing (passive propulsion)
Components of the swing phase
40% of gait cycle
- Initial swing
- Mid-swing
- Terminal swing
What is the ACSM guideline for setting proper seat height for the cycle tests?
Adjust seat height so subjects knee is flexed 5 degrees with foot in downward position
What are the 4 professionally guided pre-activity screenings
- PAR-Q (participant activity readiness questionnaire)
- health history questionnaire
- Medical history
- Informed consent
What are the 8 positive risk factors?
- Age
- Family history
- Cigarette Smoking
- Sedentary lifestyle
- Obesity
- Hypertension
- Dyslipidemia
- Prediabetes
What is the positive risk factor?
high HDL cholesterol
progressive loss of elasticity of the arteries that occurs throughout the lifespan
arteriosclerosis
form of arteriosclerosis characterized by the accumulation of plaque and lesions on/within intimate of arterial wall
atherosclerosis
explain the atherosclerotic process
- Endothelium is injured and growth factors are released
- Monocytes attach to endothelium
- Migrate to intima
- Take up cholesterol and form fatty streaks
- Platelets adhere to endothelium and growth factors are released
- Fibromuscular plaque is formed that narrows lumen
What is myocardial ischemia?
myocardial oxygen demand is greater than oxygen supply because there is insufficient blood flow to the myocardium
what is the outcome of significant coronary atherosclerosis
angina pectoris
what is angina pectoris?
discomfort in cheeks, jaw, neck, shoulder, upper back, chest
what type of angina pectoris results from coronary vasospasm?
vasospastic/prinzmetal’s
irreversible necrosis of the myocardium resulting from prolonged ischemia
acute myocardial infarction
lifestyle factors associated with diabetes mellitus
diet, exercise (sedentary), obesity
type 1 va type 2 diabetes
type 1: insulting dependent, body isn’t making it
type 2: adult onset, insulin resistant
what is metabolic syndrome?
a condition where several cardiovascular disease risk factors are clustered together
“alveoli enlarge with no elastic properties” this describes what pulmonary disease?
emphysema
“narrow airways” describes what pulmonary disease?
asthma
explain the steps of risk stratification?
- are they low moderate or high risk?
- do they need a medical exam prior to exercise?
- do they need diagnostic exercise testing prior to exam? (moderate vs. vigorous)
- does a physician need to be present? (max vs. sub max)
risk factors: age
Men >45
Women >55
risk factors: cigarette smoking
current, quit within 6 mo., environmental exposure
risk factors: family history
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