67 terms

Ex. Phys. Exam 1 CH 4

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Increase / Decrease:
increase intensity ----> ___ duration
decrease
Increase / Decrease:
increase duration ----> ___ intensity
decrease
Increase / Decrease:
increase anaerobic ----> ___ aerobic
decrease
Increase / Decrease:
increase aerobic ----> ___ anaerobic
decrease
Increase / Decrease:
increase intensity ----> ___ anaerobic
increase
Increase / Decrease:
increase duration ----> ___ aerobic
increase
Exercise is rarely ______ or ______, it is a combination of both
aerobic; anaerobic
- less than 10 sec activity: primarily ______
>less than 5 sec: ______
>5 sec - 2 min: ______
- greater than 2 min activity: primarily ______ via oxidative phosphorylation
anaerobic pathways; creatine phosphate; glycolysis; aerobic
Initiation of exercise:
- there is an immediate increase in demand for ____ within the muscles
- ______ uptake increases rapidly
ATP; oxygen
Body reaches steady state within 1-4 min of _______ exercise
light-moderate
While at steady state, ATP requirement is met through _______ ATP production
aerobic
_______ consumption (VO2) is symbolic of aerobic metabolism
oxygen
Lag in oxygen uptake at beginning of exercise
oxygen deficit
Suggests anaerobic pathways contribute to total ATP production during beginning of exercise
oxygen deficit
Anaerobic pathways for ATP production: (2)
CP; anaerobic glycolysis
Factors affecting the O2 deficit: (2)
training status; intensity of exercise
Trained person is _______ O2 deficit aka reaches stead state faster and uses more O2
Untrained person is _______ O2 deficit aka takes more time to reach a steady state and uses less O2
lower; greater
Intensity of exercise:
Intense exercise = ______ O2 deficit
greater
A trained person has greater _______ and ______, leading to earlier production of ATP via ______ pathways
bioenergetic; cardiorespiratory capacity; aerobic
Recovery from exercise:
- ____ demand remains elevated following exercise
- length of demand is related to primarily ________ and to an extent exercise ______
O2; intensity of exercise; duration;
Oxygen demand remains elevated following exercise is called... (2)
-Classic term: oxygen debt
-Contemporary term: EPOC
("excess post-exercise oxygen consumption")
higher intensity = ____ EPOC
high
"Fast" portion of EPOC: (2)
- resynthesis of stored PC
- replacing muscle and blood O2 stores
"Slow" portion of EPOC: (4)
- elevated heart rate and breathing (higher energy need)
- elevated body temperature (higher metabolic rate)
- elevated epinephrine + norepinephrine (higher metabolic rate)
- conversion of lactic acid to glucose (gluconeogenesis)
Conversion of lactic acid to glucose
gluconeogenesis
Short-term intense exercise is dominated by _____ and _____ pathways
- Less than 5 s = primarily depends on ______
- Up to 2 min = primarily depends on _______
CP; glycolytic; CP; glycolysis
-Prolonged exercise utilizes _______ pathways that can maintain steady state ATP supply indefinitely for extended exercise. Fuel sources: (3)
aerobic; carbs; fats; proteins
Body can not reach a steady state if: (2)
prolonged exercise in a hot/humid environment OR
prolonged exercise at high intensity
Maximal amount of oxygen that can be utilized by the exercising individual
VO2 max
One of the most measured variables in exercise physiology
VO2 max
- VO2 ________ linearly with increasing work rates
- VO2 max = upper ceiling to _______ consumption
increases; oxygen
One of the most valid ways of quantifying cardiorespiratory fitness
VO2 max
VO2 max influenced by: (2)
Training and Genetics
VO2 max represents maximal ability of: (2)
- CR system to deliver oxygen to muscle
- Muscle to utilize oxygen and transport ATP
high VO2 = _____ cardiorespiratory fitness
high
low VO2 = _____ cardiorespiratory fitness
low
Lactate Threshold:
- Low intensity exercise:
> ATP production primarily _____
> lactate concentration in blood is _____
- High intensity exercise:
> blood lactate concentrations _____
aerobic; low; rise
Mechanisms for lactate threshold: (4)
1. low muscle oxygen
2. accelerated glycolysis
3. recruitment of fast-twitch muscle fibers
4. reduced rate of lactate removal from the blood
Practical uses for lactate threshold: (2)
- prediction of performance
- marker of training intensity
Lactate threshold:
- trained person = LT occurs @ _____ of VO2 max
- untrained person = LT occurs @ _____ VO2 max
80%; 50%
RER stands for:
respiratory exchange ratio
Estimation of fuel utilization during exercise can be measured by:
respiratory exchange ratio (RER or R)
RER measures the ratio of ____ produced to ____ consumed
CO2; O2
Estimation of fuel utilization during exercise:
Carbohydrate...
Glucose = C6H12O6
C6H12O6 + 6O2 ---> 6CO2 + 6H2O + 36 ATP
RER = VCO2/VO2 = 6 CO2 / 6 O2 = 1.00
Estimation of fuel utilization during exercise:
Carbohydrate...
Glucose = C6H12O6
C6H12O6 + 6O2 ---> 6CO2 + 6H2O + 36 ATP
RER = VCO2/VO2 = 6 CO2 / 6 O2 = 1.00
Estimation of fuel utilization during exercise:
Fat...
Palmitic acid = C16H32O2
C16H32O2 + 23O2 ---> 16CO2 + 16H2O + 128 ATP
RER = VCO2/VO2 = 16 CO2 /23 O2 = 0.70
Estimation of fuel utilization during exercise:
Fat...
Palmitic acid = C16H32O2
C16H32O2 + 23O2 ---> 16CO2 + 16H2O + 128 ATP
RER = VCO2/VO2 = 16 CO2 /23 O2 = 0.70
RER indicates fuel utilization:
- RER of 0.70 = ______
- RER of 1.00 = ______
- RER of 0.85 = ______
100% FAT
100% CARB
50% fat / 50% carb
During steady-state exercise, VCO2 and VO2 is reflective of ____ consumption and ____ production at the cellular level
O2; CO2
The higher the intensity, the ______ the RER
higher (carbs used)
Factors affecting fuel selection: (3)
- intensity of exercise
- duration of exercise
- training and dietary status
FAT is the primary source during ________ exercise and CHO (carb) is used during ____________ exercise
low intensity; short term, high intensity
Exercise intensity at which CHO exceeds FAT as fuel substrate (~40% of VO2 max)
cross over point
There is an increased utilization of _____ as intensity increases
CHO
Factors responsible for crossover from FAT → CHO: (2)
recruitment of fast twitch fibers; increased blood levels of epinephrine
Recruitment of fast fibers:
- FT fibers store more _______ + are lower in ________ and lipolytic enzymes so they are more able to burn CHO than fats
glycogen; mitochondria
Increasing blood levels of epinephrine during CROSSOVER:
- Epinephrine stimulates _______ (adding Pi's)
> increases rate of glycogenolysis + glycolysis
> increased glycolysis increases lactate which inhibits _______ (breakdown of fats)
> as a result, more _____ is used and less fat is metabolized
phosphorylase; lipolysis; CHO
______ is used at onset of light-moderate work, but prolonged exercise leads to a shift from CHO metabolism toward _____ metabolism
CHO; fat
Duration: Rising blood levels of epinephrine increases the rate of _______ during prolonged exercise. This leads to the breakdown of triglycerides into glycerol and free fatty acids aka FFA (lipases)
lipolysis
Lipolysis is a slow process so it takes a while for it to increase plasma _______ levels for energy (~20 min). After about 20 min is when the body will switch back over to primarily using ______ over CHO
FFA; fat
Fuel source:
Onset of exercise= ______
Crossover= ______
Prolonged exercise= ______
FAT
CHO
FAT again
During prolonged exercise, there is a shift from ______ to ______ metabolism
CHO; fat
Training Status:
- endurance training increases capacity to utilize _____
- ________ occurs at a higher % of VO2 max
*serves to "spare" precious muscle ______
fat; crossover; glycogen (carb)
Nutritional Status:
- high FAT diets increase use of _____ for energy
- high CHO diets increase use of _____ for energy
FAT; CHO
"Fats burn in a carbohydrate flame" aka fats can not be used as an energy source if carbs are not present
"Fats burn in a carbohydrate flame" aka fats can not be used as an energy source if carbs are not present
_________ depletion during prolonged high-intensity exercise leads to fatigue
Glycogen
Sources of fuel during exercise: (4)
carbohydrate (stored and ingested)
fat
protein
blood lactate
Sources of CHO during exercise: (3)
muscle glycogen; liver glycogen; blood glucose
Muscle Glycogen (*80 min) → ~16 miles
~ 400 grams or 1600 kcal
Liver Glycogen (*16 min) → ~4 miles
~ 100 grams or 400 kcal
Blood Glucose (*2 min)
~ 5 grams or 20 kcal
...