KINS 308 - Exam 2 TA Version

work

force applied against gravity over distance (J)

What is a better measure of exercise performance? work or power

Power

calculating work

mass x distance x pace x time = work (kgm)

power

work expressed relative to time (kgm/min) or Watts.

calculating power

work/time = power kgm/min

converting power to watts

kgm/min / 6.118

converting power to kcal/min

kgm/min x 0.00234

converting kcal/min to kJmin

kcal/min x 4.186

calorimetry

the science that quantifies heat released from metabolism (metabolic rate)

vo2

oxygen consumption

what is resting vo2

0.25 L/min

vco2

carbon dioxide production

what is resting vco2

0.2 L/min

RQ

respiratory quotient (co2 / o2 for the cell)

RER

respiratory exchange ratio (vco2 / vo2 measured from expired air)

FiO2

fraction of inspired oxygen = 0.20

FiCO2

fraction of inspired carbon dioxide = 0.0003

FiN2

fraction of inspired nitrogen = 0.79

calculation vo2

vo2 = (Vi x FiO2) - (Ve x FeO2)

Haldane transformation

Vi = Ve x [1 - (FeO2 + FeCO2) / FiN2]

John Scott Haldane

Graham Lusk

caloric equivalent to calculate caloric expenditure

5 kcals/LO2

3 metabolic changes during exercise

phosphagen system
glycolysis
aerobic/mitochondrial respiration

what is the rest to exercise transition?

VO2 increases rapidly until:
-steady state (w/n 3-5 min): all metabolic needs are being met
-ATP demand met aerobically: state of increased mitochondrial respiration

rise of vo2 in an untrained person

slower response time to steady state (can improve through aerobic training)

what is the relationship between exercise intensity and vo2?

higher intensity requires higher vo2

what is steady state exercise?

all metabolic demands are being met through mitochondrial respiration (takes 3-5 minutes)

Why is there a lower time to steady state when trained?

mitochondria are stimulated faster to meet demand due to increase mass and oxidative enzyme activity (safe effect during warm up)

effect of intensity on rest to SS transition

the larger the increment the longer the time to SS

oxygen deficit

O2 consumption is lower than necessary to supply appropriate ATP production required of any exercise

why to oxygen deficit reflect an increase in anaerobic metabolism?

-increased CrP and glycolysis to meet demands
-delay time for full mitochondrial contribution

would trained people have a lower o2 deficit than untrained person for given exercise intensity?

trained person has a lower deficit because they have more mitochondria and enzymes and there

what advise would you give to someone so that the compete at their top performance?

stimulate mitochondria before the race (30-40 min) with a dynamic warm-up

what is the body's response to prolonged exercise (exercise longer than 10 minutes)?

-ATP primarily from mitochondrial means
-steady state exercise can be maintained

what is the body's response to intense exercise?

-vo2 increases rapidly
-CrP decreases rapidly (more intense=bigger decrease especially in FT motor units)
-increase in glycolytic rate (increases PFK and phosphorylase activity)
-increase in lactate production and release
-increase in muscle and blood acidosis

What is the body's response to incremental exercise?

vo2 increases non-linearly to vo2 max

vo2 max

maximum oxygen consumption
-"fitness" or "exercise performance" measure
-quantifies exercise intensity
-expresses intensity as a percent
-#1 predictor of morbidity

What are the units used to express vo2 or vo2 max?

-meters/min
-mL/min
-ml/kg/min

why is it important to express vo2 max in ml/kg/min when making comparisons?

difference between male and female and body mass

what is greatest above lactate threshold?

-lactate production and release
-glycolytic rate and acidosis

what is the lactate threshold?

point where lactate production exceeds it's removal
-curvilinear response with increase exercise intensity

LT in untrained people

40-60% of vo2 max

LT in trained people

greater than 70% of vo2 max

what is the point of maximal ss exercise?

when max intensity ss is maintained

factors of LT physiology

-represents increase in anaerobic metabolism
-can't maintain prolonged exercise above LT
-large increase in glycogenolysis above LT
-recruitment of fast-twitch motor units

what is the best measurement for predicting performance?

exercise intensity at LT (middle to long distance events)
-higher LT = faster one can sustain pace

cells that produce glucose?

liver and kidney

glycogen synthesis

glucose to glycogen

glycogenolysis

glycogen to glucose

gluconeogenesis

making glucose from other sources than CHO (glycerol, amino acids, and lactate)

why is gluconeogenesis needed?

-Energy for brain
-When blood glucose levels are low
-Glycogen stores are low

what is the source of fat during lower intensity exercise?

Plasma FFA (adipose tissue)

what is the source of fat during moderate to high intensity exercise (usage affected by training status)?

Intramuscular TGL

what are amino acids used for during exercise?

an emergency source via gluconeogenesis
-can increase up to 10-15% in prolonged exercise but little used during rest

what is the purpose to metabolism?

maintain blood glucose homeostasis

fuel selection during low-intensity exercise (less than 30% vo2 max)

fats are primary fuel

fuel selection during high-intensity exercise (greater than 70% vo2 max)

CHO are primary fuel

"crossover" concept

shift from fat to CHO as exercise intensity increases

what causes the shift in fuel during "crossover"?

recruitment of FT MUs increasing blood levels of Epi (increasing rate of glycolysis overtakes beta-oxidation for ATP)

fuel selection during prolonged exercise

shift from CHO toward fat metabolism

what causes increased rates of lipolysis?

the increase of lipase activity (activated by catecholamines)

what does increased rates of lipolysis cause?

decreased muscle glycogen stores (greater than 2 hours with moderate to high intensity)

The lower the ________ and the better the _________________, the longer the time to muscle glycogen depletion

exercise intensity
training status

fuel mix during prolonged exercise

glycogen early (30-45 min) ---> glucose and FFA usage increases ---> glucose usage decreases and FFA usages increases (greater than 60 minutes) ---> protein usage slowly increases as glucose decreases

components of the cardiovascular system

-heart and blood
-systemic circulation
-pulmonary circulation

purposes of the cardiovascular system

-deliver o2 to tissues and transport co2 to lungs
-transport nutrients and hormones to tissues
-maintain thermoregulation and blood pH
-maintain blood pressure

how many liters of blood are in the system?

5 liters

what is hematocrit?

percent of RBCs in blood
-40-45% in males
-35-40% in females

how do you blood dope?

-remove one unit of blood every 4-8 weeks up to 3 times
-reinfuse one week prior to competition

superior vena cava

right coronary artery

inferior vena cava

aorta

pulmonary trunk

great cardiac vein

left anterior descending artery

right pulmonary artery

tricuspid valve (right AV valve)

chordae tendinae

papillary muscle

aortic valve

left pulmonary artery

pulmonary valve

bicuspid valve (mitral valve)

how does the myocardium work?

-myocardial cells are interconnected
-action potential spreads from cell to cell to promote synchronicity
-high amount of ST muscle fibers (no motor units)

is the myocardium highly aerobic or anaerobic?

aerobic (lots of mitochondria and capillaries)

why are veins considered high compliance vessels (capacitance vessels)?

can hold increased blood volumes and contain valves to direct flow one-way

why are arteries considered windkessel vessels?

property provides constant blood flow

arterioles

-primary function = blood flow regulation
-contain smooth muscle (SNS controlled)
-resistance vessels = decreased blood velocity

capillaries

-exchange of gases and nutrients
-thin walled, one layer of cells (porous)

venules

-fluid and molecule exchange
-on venous side of capillaries

what vessel has the lowest velocity?

capillaries (allows for gas exchange)

what vessels have the highest cross sectional area?

capillaries and veins

what vessel has the greatest drop in pressure?

arterioles

Is cross sectional area higher in pulmonary capillaries or systemic capillaries?

pulmonary capillaries

what are the catecholamines in the blood?

epinephrin and norepinephrine

cardiac output (Q)

volume of blood pumped per minute
Q = HR x SV
Avg = 5 L/min

stroke volume (SV)

volume of blood ejected per beat (ml/beat)
SV = EDV - ESV

EDV

end diastolic volume