Exam 3 Review - lectures Flashcards
Equation for Stroke Volume
EDV-ESV
Equation for Ejection Fraction
SV/EDV
Normal Q
5 L/min
What is innervated by the sympathetic system in the heart
SA node, AV node, and the myocardium
What does an increase in sympathetic tone do
Increase contractility of the heart
How do you change sympathetic and parasympathetic tone
Higher brain centers, Chemoreceptors, Muscle Receptors, and Systematic Receptors influence the Medulla - with the vasomotor and cardiac center
Increase in sympathetic tone is caused by
Increased T (hypothalamus)
Increased emotional stress (cerebral cortex)
Increased movement (mechanoreceptors)
Increased PCO2, Increased H+, or Decrease PO2 (chemoreceptors)
What happens to SV when you go from laying down to standing up
It decreased due to the influence of gravity
What happens to SV when you go from laying down to running
Increase in SV
HR vs treadmill speed acute exercise
Linear increase in HR until you reach the HR max
What happens to HR, Qmax, and VO2max with age
All will decrease
Is HRmax a limit of speed?
No, it only limits the CV system
Does SV plateau, and if so, when?
Yes at about 40-60% of max intensity
What happens to EDV in acute exercise w/increase intensity and why
It increases until about moderate intensity due to an increase in venous return causing greater stretch and therefore a greater contraction. After it plateaus
What happens to ESV in acute exercise w/increase ex intensity and why
Not much change to it - If contractility increases it will decrease
What is Qmax
The point at which the heart cannot pump more blood
What happens to SBP with low-mod Intensity acute aerobic exercise
It increases due to the increase in Q
What happens to DBP with low-mod Intensity acute aerobic exercise
It decreases a little or it stays the same due to a reduction in peripheral resistance
What is the simple equation for MAP
1/3(SBP-DBP) + DBP
What happens to TPR with low-mod Intensity acute aerobic exercise
It will decrease due to vasodilation
What is the Rate Pressure Product (RPP)
It is a measure of the workload on the heart - HR x SBP
What happens to RPP with low-mod Intensity acute aerobic exercise
It plateaus
What happens to SV, HR, and Q with low-mod Intensity acute aerobic exercise
All will increase but are limited by max HR and SV
What is CV drift
A heart rate increase even with steady state exercise to try to compensate the decreased SV due to increased sweating - this is exacerbated in a hot environment
How can you limit CV drift
Fluid replacement during exercise
What happens to Q during acute maximal aerobic exercise
It will increase to a point but will level off - around same point as HR max
Can you keep increasing workload past the max Q
Yes it is possible
What happens to HR during acute maximal aerobic exercise
It will increase to a point but will level off - around same point as Q max
What occurs with SBP in acute maximal aerobic exercise
Increase to a point but stop bc Q will stop increasing
What occurs with DBP in acute maximal aerobic exercise
It stays flat because any changes are offset are due to the massive vasodilation that occurs
What occurs with MAP in acute maximal aerobic exercise
It increases due to the increase in SBP
What occurs with TPR in acute maximal aerobic exercise
It will reduce with an increased workload due to the increased vasodilation of the vessels
What occurs to RPP in acute maximal aerobic exercise
It increases and plateaus near the Q max and SBP max
Do HR, VO2, and Q share a common max in acute maximal aerobic exercise
Yes - they all increase to around the same point
Q and VO2 in UE vs LE (acute)
Q and VO2 are lower in UE than LE due to less muscle mass being utilized
Difference of HR max UE vs LE (acute)
It is the same max value for both, it just occurs at a lower VO2 for UE
SV in UE vs LE (acute)
SV decreases in UE due to less vasodilation since there is less muscle mass recruited and therefore a higher TPR
MAP in UE vs LE (acute)
Q is the same at any given VO2, but TPR lower in LE so lower MAP
RPP UE vs LE (acute)
It is higher in UE because of higher TPR in UE so heart has to do more work
What kind of overload do you get with (acute):
A: Aerobic training
B: Resistance training
A: Flow overload
B: Pressure overload
(acute) HR and
A: Aerobic Training
B: Resistance training
A: Increase a lot more than just static
B: modest increase due to resistance to blood flow (decreased SV due to increased afterload)
(acute) BP and
A: Aerobic Contraction
B: Resistance Contraction
A: Some increase - mainly milks muscles to increase flow/venous return
B: Sharp rise in BP due to contracting venous blood flow, therefore increase TPR to increase V and SBP and DBP due to large afterload
(acute) Q and
A: Aerobic Training
B: Resistance training
A: higher bc SV and HR increase (increase Q due to increased demand -flow overload: increase venous return to increase EDV)
B: lower due to lower SV
(acute) BP and
A: Aerobic Training
B: Resistance training
A: Increase SBP, no change DBP
B: increase SBP and increase DBP (due to TPR) - note: LE > UE
What happens to blood flow when you increase sympathetic tone (acute)
Increased SV and Q due to compressing the venous volume so more return to heart
Where is most of the blood at rest
On the venous side (64%)
What is the primary determinate of flow
Vasomotion
What is sympathetic effect on vessels
Vasoconstriction - leads to a change in blood flow
Relative changes of blood flow during acute exercise Muscle flow - Renal and GI - Heart- Brain - Skin -
Muscle flow - 80-90% Renal and GI - decrease Heart- same Brain - reduced Skin : increase with intensity to high intensity
Absolute changes of blood flow during acute exercise Muscle flow - Renal and GI - Heart- Brain -
Muscle flow - large increase towards the working muscle, proportional to muscle mass working
Renal and GI - decrease with intensity
Heart- increase proportional to intensity
Brain - no change (areas in brain and activity changed)
Can you increase O2 consump of working tissue without changing Q?
Yes - due to the change in distribution of blood flow to the heart, lungs, and working tissue
What is the Fick equation
VO2 = Q x a-vO2 diff
Acute Central changes in Q and a-vO2 to alter VO2 max:
Change HR or SV to alter ability to move O2
Change blood volume to increase flow
Change Hb to increase carrying capacity
Acute Peripheral changes in Q and a-vO2 to alter VO2 max:
Alter flow to the nonexercising regions to improve a-vO2 diff
Increased amount of capillaries for O2 exchange in the working tissues
Endurance training and VO2 max (chronic)
Considerable increase
Q and a-vO2 also increase due to increase SV
What happens to SV relative to VO2 with endurance training (chronic)
It will be higher at any given VO2 (due to increase in EDV)
What is the adaptation to EDV with endurance training (chronic)
It will be higher at any given workload - even at rest
What happens to the Left Ventricular Volume with endurance training (chronic)
It will be higher to lead to increased SV
What happens to the heart with endurance training (chronic)
Increased left ventricular mass and change in the direction of the muscle fibers to allow for higher force of contraction
What happens to HR with endurance training (chronic)
The HR will be lower at any given workload, even at rest
Normal values of components of Q at rest pre training adaptations
HR: 70bpm
SV: 70 ml/min
Q: 4.9 L
Normal values of components of Q at rest post training adaptations
HR: 54 bpm
SV: 90ml/min
Q: 4.9ml/min
Is HR max different post endurance training?
It is the same value it just occurs at a higher workload due to the overall decrease in HR at any given time
What happens to Q with endurance training at rest, during submax, and max (chronic)
Rest: unchanged
Submax: unchaged
Max: higher due to increased SV max
What is the Karvonen Method
Calculate HRR and find training sensitive zone
Karvonen Method Equation
0.6(MHR - RHR) + RHR
Does it take longer or shorter for HR to return to baseline post training (chronic) and the caloric significance (EPOC)
It takes a shorter amount of time, lowering EPOC and post-exercise calories consumed
What is a normal a-vO2 dif at max
5 ml O2/dL
What happens to the a-vO2 diff with endurance training (chronic)
It will be improved due to a reduction in venous O2 content (due to better O2 consumption by vasodilation and constrict to properly direct flow of blood)
What happens to BV with endurance training - chronic
Increase due to increased water retention and increased plasma volume
Chronic adaptations to CV at rest with resistance training
No change: Q, VO2 max, HR (ex and rest)
Some increase: LV mass
What are the central factors that can change VO2 max
Q, HR, SV
What are the peripheral factors to increase VO2 max
Increased BV, plasma, RBCs Increased a-vO2 diff Increased flow to working muscles Increased capillarity (working muscles) Increased myoglobin and enzymes
What events are actually easier to do good in at a high altitude and why (acute)
Power events due to less air resistance from the decreased pressure
What are some of the cognitive effects of increased altitude (acute)
Slow and slurred speech, decreased reaction time, decreased light sensitivity, decreased visual acuity
Does O2% of air decrease with high altitude?
No - it is the PO2 that decreases, not the % O2 of the air
What happens to the a-vO2 diff with increased altitude (acute)
It is decreased to almost no difference at all causing very marginal ability of gas diffusion
As you increase in altitude, does blood become more acidic or alkalotic? Why? (acute)
It becomes more alkalotic due to blowing off more CO2 as a result to the increase of O2 as the driver of respiration
What occurs to PCO2 with increases in altitude
It decreases
Where is the “sudden death” height
2000m
What are the acute changes to VO2 max with increasing altitude
VO2 max declines considerably past 2000m due to the decrease in PO2
Acute change to Ve with increased altitude
Increased due to increased frequency of breaths
Acute change in oxy hemoglobin curve with increased altitude
The curve will shift to the left due to the lower PO2 and loss of CO2
Chronic change in oxy hemoglobin curve with increased altitude
Curve shifts back to the right due to renal compensation to lose HCO3
What happens to Ve with increased altitude (chronic)
Increase Ve
What happens to blood volume with altitude acclimatization
It will eventually increase back to normal values
What happens to heart rate with altitude acclimatization
It will decrease towards normal/sea level because the stroke volume will return to normal levels
What happens to these values with increasing altitude (initial): VO2 max Submax VO2 HR rest & submax Ve BV PCO2 PaO2
VO2 max: ↓ Submax VO2: ↑ HR rest & submax: ↑ Ve: ↑ BV: ↓ PCO2: ↓ PaO2: ↓
What happens to these values with increasing altitude (adapted): VO2 max Submax VO2 HR rest & submax Ve BV PCO2 PaO2
VO2 max: ↑ (due to higher BV) Submax VO2: ↓ HR rest & submax: ↓ (due to higher BV) Ve: ↓ BV: ↑ PCO2: ↑ PaO2: ↑
What happens when you return to sea level after altitude acclimitization?
Changes are reversed w/in two weeks -
BC gradual come back to normal thru loss in urine
Altitude vs Blood Doping - benefits
With altitude you can legally accomplish the increase in Hct in a legal manner - just has to be timed out properly
List the factors that go into thermal balance
Radiative Conductive Convective Evaporative Metabolic
Equation for thermal balance
M ± R ± C ± K - E = 0
What accounts for 80% of heat loss during exercise
Evaporation through sweat
Where does sweat come from
the extracellular fluid - interstitial and plasma V
What happens to VO2 as sweating increases? Why?
Vo2 will decrease -
Plasma V decrease, SV decrease, Q decrease, VO2 decrease
What are the main ways we lose heat
Evaporative and convective
What are the main ways we gain heat
Metabolism
Radiative
Conductive
Where in the brain do we control temperature
In the hypothalamus - we can adjust our set point
How do we adjust thermoregulation
Change blood flow to skin and veins
Increase output to sweat glands
Change behaviour to influence the kinds of clothes that we wear
Do adjustments in set points always work?
No - once you get over about 40 C heat stroke can become possible
Core T vs WBCT
The higher the intensity of exercise at any given environmental T, the higher the core temperature will be. Max exercise limited quicker at higher environmental Ts
What can the sweat rate increase to at high intensities or temperatures? Why is this significant
1.5 - 2L
Significant because it is a large decrease in plasma volume so fluid replacement is important
What happens to SV with acute exercise in heat
It will decrease due to more blood volume going to cutaneous blood flow
What will happen to HR with acute exercise in heat
It will increase due to the decreased SV
What happens to VO2 with acute exercise in heat? Why is this important
It gets higher faster leading to faster glycogen depletion and higher lactate levels so time to failure is sooner
What occurs to RPP and TPR during acute exercise in heat
TPR will decrease due to the vasodilation of the skin so RPP will also decrease
How long does it take to acclimate to the heat? At what intensity?
About 2 weeks for all of the adaptations to occur
Moderate to high Intensity required, otherwise the timeline stretches out
What happens to sweat rate with heat acclimatization
Sweat more at lower T causing less blood to flow to the skin so it can stay with the working muscles
What happens to x with heat acclimatization: BV SV HR RPE
BV: not decrease as much
SV: increased (compared to initial heat exposure)
HR: lower (not as low as normal conditions)
RPE: lower (can do more exercise)
Which substrate do we use more of after heat acclimatization?
We use more fat so we get less lactate accumulation and less glycogen depletion
What happens to core body T with heat acclimatization?
It is lower at all durations and intensities of exercise than before acclimatization
What happens to time to fatigue in 4-11 C weather
It is improved - able to work for longer time due to improved VO2 max
What is the ideal T range for aerobic exercise
35-50 F
Describe the ways the body tries to conserve heat
Shivering - muscle contractions to generate heat
Nonshivering thermogenesis- brown adipose tissue (small amount)
Peripheral vasoconstriction: reduce blood flow to skin
What are the factors that affect heat loss
Body size and composition (obese = more insulation and ability to maintain heat)
Air T & Wind Chill : Conductive & Convective heat loss
Water immersion: much easier to lose heat and therefore t to survival is lower
Short term cold exercise responses
Muscle weakening and faster fatigue
Increased water loss (from respiration)
Increase HR
Greater carbohydrate mobilization and less FA transport
Can we acclimate to the cold?
Partially but the response is different in each person and none of the changes are life saving
What is cold habituation
A type of acclimatization to the cold that is blunted shivering and less cutaneous vasoconstriction
What is metabolic acclimation
A type of acclimatization to the cold that is an enhanced ability to shiver
What is insulative acclimation
A type of acclimatization to the cold that is enhanced vasoconstriction and improved muscular blood flow
t of survival in water immersion and cold acclimation
15-20 minutes if 32-40 F, lethal after one hour no matter if acclimated or not
In the HH, HL, and LL groups, what happened to plasma volume
There was no significant difference
In the HH, HL, and LL groups, what happened to BV
It decreased in LL but no other differences
In the HH, HL, and LL groups, what happened to Hct and Red cell mass
Increased HL and HH
In the HH, HL, and LL groups, what happened to performance
faster in HL and HH
In the HH, HL, and LL groups, what happened to VO2 max
HH and HL improved due to the altitude exposure
In the HH, HL, and LL groups, what happened to change in steady state VO2 (ventilatory threshold VO2)
Increased most in HL group leading to an increased ability to work out at a higher intensity
In the HH, HL, and LL groups, what happened to 5k performance time
LL decreased making HL and HH appear to increase more than they actually did
What are the main takeaways of the detraining paper study starting in 1966
Living a sedentary lifestyle (/3 weeks of extreme bed rest) is worse for your body than aging 30 years
Regardless of age, aerobic exercise will improve CV function
What is the overall ACSM recommendation?
> 30 min moderate/day for >5days/week or >20 min vigorous/day >3 days/week or mix of moderate/vigorous for E expenditure of >500-1000 MET/week
General process for ACSM recommendation
Committee of experts Inclusion/exclusion criteria Data Review Group breakdown to research External Review Edit & add data that was missed Approval
What is the focus of the ACSM recommendation
CV and metabolic health - to decrease risk of heart disease, diabetes, etc.
Recommendations for frequency
> 5 days/week mod or 3 days vigorous or combo 3-5days
What happens to risk of heart disease as we increase walking intensity
It is decreased
Time recommendation
30-60 minutes of moderate, or 20-60 minutes of vigorous
Can exercise be split into bouts and still meet the daily needs?
Yes - you can accumulate your exercise periods
Can steps be used to fulfill the time recommendation for exercise?
It can be used as a rough estimate for exercise volume. >7000 steps a day is the goal, and if intensity if up, it is helpful.
What is the Intensity recommendation for exercise? How is it calculated?
Moderate to vigorous intensity
Karvonven method: 30-39 light, 40-60 moderate, vigorous 60-90
What was found with BMI or age and intensity?
No matter the BMI or age, exercising at higher intensities will show CV improvements
What has been found regarding sitting time and heart health?
In a sedentary population, standing instead of sitting will show improvements in heart health. If you already exercise mod-vig daily, then there is no change in heart health.
What is the recommendation for exercise type?
Any sort of aerobic exercise that you will consistently do each day is a good recommendation.
