6: cardiorespiratory endurance

Question 1

what is the breathing rate at rest?

Answer 1

12-20 breaths/minute

Question 2

What is the heart rate at rest?

Answer 2

50-90 beats/min

Question 3

What is the cardaic output at rest?

Answer 3

5L/min

Question 4

What is blood distribution to muscles at rest?

Answer 4

15-20%

Question 5

during exercise what is the breathing rate

Answer 5

40-60 breaths/min

Question 6

During exercise what is the heart rate?

Answer 6

170-210 beats.min

Question 7

What is the cardiac output during exercise

Answer 7

25L/min

Question 8

What is the percentage of blood distributed to muscles durign exercise?

Answer 8

85-90%

Question 9

Ventilation

Answer 9

increases with exercise to meet the increased demand of gas exchange

during exercise; ventilation can increase from 6L/m at rest to over 150L/min during maximal exercise and to more than 200L/min during maximal voluntary breathing

with exercise/endurance training, the lungs become more efficient in gas exchange

Question 10

Cardiac output (Q)

Answer 10

amount of blood pumped per unit time (usually a min)

Q (L/min) =HR x SV

Question 11

Stroke volume (SV)

Answer 11

the amount of blood that is ejected or pumped from the LEFT ventricle during systole.

SV = vent. volume - amoutn left

@ rest = 70ml/beat
@ max = 190 ml/breat

Question 12

during exercise what is the cardiac output distribution compared to at rest?

Answer 12

blood flow at rest is evently set out whereas during exercise, most of the blood flow is to the muscles

Question 13

Heart heart reserve (HRR)

Answer 13

HRR = Max HR - Resting HR

Question 14

oxygen uptake:

Answer 14

the amount of oxygen that is consumed by the body due to aerobic metabolism
measured: volume of oxygen that is consumed (vo2) in a given time
incareases in relation to the maount of energy that is required to perform an activity

Question 15

Vo2max

Answer 15

a measure used to evaluate the maximal volume of o2 that can be supplied to and consumed by the body

the maximal rate at which the body can take up and utilise o2.
absolute = L/min; relative = mL/kg/min

Question 16

oxygen uptake; incrreased capillarization

Answer 16

can affect the abilty fo the circulatory system to place a RBC close to tissues that are using the oxygen; this increases the ability of those tissues to extract the req’d o2 due to shorter diffusion distance

Question 17

oxygen uptake: hematocrit

Answer 17

alter the o2 uptake by increasingly or decreasing the amount of o2 that is supplied to working tissues

ability fo the tissues to extract oxygen (a-C o2 difference) directly affects o2 uptake.

Question 18

Fick Equation

Answer 18

determines the rate at which a person uses oxygen in their body – which is also known as VO2
Vo2= Q x (a-v)02 difference

Question 19

RBC

Answer 19

erythrocytes

primary fn: transport oxygen from the lungs to the tissues and remove co2 from the body

Question 20

Hematocrit

Answer 20

the percentage of the blood made up of RBCs

Question 21

Hemoglobin

Answer 21

• A protein containing iron.
• Each molecule can bond to and transport four oxygen molecules.
• The amount of oxygen that is carried by the blood is dependent upon the partial pressure of oxygen (PO2).
• The difference in the amount of oxygen that is present in the blood as it leaves the lungs and the amount of oxygen that is present in the blood when it returns to the lungs is called the arterial-venous oxygen difference (a-v O2 difference), measured in ml of oxygen per liter of blood (ml O2/L ).
• If the a-v O2 difference increases, it means that the body is using more oxygen.
• The typical a-v O2 difference at rest is about 4 to 5 ml O2/L, while during exercise the a-v O2 difference can increase to 15 ml O2/L.

Question 22

WHat is EPO?

Answer 22

erythropoeitin

a circulating hormone, is the principal factor that stimulates red blood cell formation.
secreted in response to low oxygen levels (when one goes to altitude) and also in response to exercise, thus increasing the percentage of new red blood cells in the body.

Question 23

WHere is bv produced?

Answer 23

bone marrow

Question 24

what is reticulocytes

Answer 24

new rbc

contains more hb than older rbc; carry greater amount of o2

Question 25

EPO production

Answer 25

high altitude (low o2 level) has an effect on EPO production, which in turn generates a high production of RBC

Question 26

VO2 max as a predictor of performance

Answer 26

* In elite athletes, VO2 max is a good but not a great predictor of performance. * VO2 max represents an athlete’s aerobic potential speed at a given VO2 may be more important. * Same level of aerobic power but one may reach their VO2 max at a running speed of 20 km/hr and the other at 22 km/hr. Running economy (RE) is the energy demand for a given velocity of submaximal running. * Lactate threshold- more predictive of performance (the speed at lactate threshold vs actual value itself).

Question 27

lactate threshold

Answer 27

the pt at which white blood lactic acid suddenly rises during incremental exercise aka anaerobic threshold practical uses in prediction of performance and as a marker of exercise intensity

Question 28

Lactate (LA) accumulation

Answer 28

LA accumulation = LA production - LA removal

Question 29

Other mechanisms for lactate threshold

Answer 29

failure of the mito hydrogen shuttle to keep pace with glycolysis - excess NADH in sarcoplasm favours converion of pyruvic acid to actic acid

Question 30

Type of LDH:

Answer 30

- enzyme that converts pyruvic acid to lactic acid | - LDH in fast twitch fibres favours formation of lactic acid

Question 31

Source of fuel during exercise:

Answer 31

- CHO (blood glucose, muscle glycogen) - fat (plasma FFA 9from adipose tissue liipolysis); intramuscular triglycerides - protein (only a small contribution to Total energy production) (may increase to 5-15% late in prolong exercise - blood lactate (gluconeogenesis via the Cori cycle)

Question 32

Exercise duration and fuel selection

Answer 32

- during prolong exercise there is a shift from CHO metabolism toward fat metabolism - increased rate of lipolysis (breakdown of triglycerides into glycerol and FFA; stimualted by rising blood levels of epinephrine)

Question 33

interaction of FAT and CHO metabolism durign exercise

Answer 33

fats burn in the flame of CHO glycogen is depleted during prolong high intensity exercise - reduced rate of glycolysis and production of pyruvate - reduced krebs cycle intermediates - reduced fat oxidation (fats are metabolized by krebs cycle)

Question 34

respiratory exchange ratio

Answer 34

the ratio between the amount of co2 exhaled and o2 inhaled one breath is the respiratory exchange ratio RER = VCo2/CO2

Question 35

Aerobic system changes with training: | Cardiovascular adaptations

Answer 35

``` cardiac hypertrophy: the "athelete's heart" plasma volume HR Sv Q oxygen extraction (a-delta difference) blood flow nad distribution BP ```

Question 36

Plasma volume

Answer 36

during exercise there is a shift of water from the plasma volume to intracellular and Interstitial spaces, thus decreasing overall blood volume

Question 37

What are the 3 major reasons for decreasing overall volume:

Answer 37

1) Sweating can reduces blood plasma volume. 2) buildup of metabolic by products in the muscle, increases its osmotic gradient, pulls water in. 3) blood pressure increases with exercise forcing water into the interstitial spaces - exercise can cause blood volume to drop as much as 10%. - impede performance as it will have a direct result on decreasing the amount of blood returning to the heart and stroke volume..

Question 38

following endurance training...

Answer 38

Due primarily to two mechanisms which increase plasma volume. 1) exercise induces the release of antidiuretic hormone and aldosterone act to retain more water and blood volume 2) endurance exercise training can increase the osmotic gradient of blood by increasing plasma proteins, especially albumin.

Question 39

Aerobic system changes with training: | pulmondary adaptation with training

Answer 39

- maximal exercise (inreaes ventilation) - submaximal exercise (tidal volumes increases and breathing frequency decreafses) - training may benefit ventilatory endurance

Question 40

Aerobic system changes with training: | metabolic adaptation with training

Answer 40

``` number and size of mito aerobic system enzymes fat and CHO metabolism muscle fibre type and size myoglobin concentration ```

Question 41

Aerobic system changes with training: | blood lactate concentration

Answer 41

decreased production | increased clearence

Question 42

common long term adaptations to endurance training

Answer 42

``` HR at rest and max decreases SV at rest and max increases Q rest and max increases heart volume increases blood volume increases Other aerobic training adaptations: ```

Question 43

Other aerobic training adaptations:

Answer 43

body comps changes (increased lean mass; decreased fat mass) body heat transfer performance changes psychological benefits