Lec 15 Substrate Utilization Flashcards
What is RER and how is it measured
Respiratory exchange ratio
Carbon dioxide produces / oxygen consumed
VCO2/VO2
Carbohydrate vs lipid as fuel
What is the RER if carbohydrates are the fuel
1.0
Carbohydrate vs lipid as fuel
What is the RER if lipids are the fuel
0.71
Carbohydrate vs lipid as fuel
What is the RER for a MIXED fuel
1.0< RER< 0.71
_____ % more energy per unit of O2 for _________ vs. ________
7.7%
For carbohydrates vs lipids
What does higher or lower RER mean
Show the intensity of exercise
Higher RER the higher the intensity
Show what type of fuel you are using
What are the five factors that influence substrate oxidation
Exercise intensity, duration, sex, substrate availability, training status
What is the main energy source at 60-65% of vo2max
Fat oxidation specifically plasma FF acid
What is the main energy source above 60-65% of vo2max
Carbohydrate oxidation
Lipids are used sparingly especially when exercise intensity is greater than 65% of vo2max
As you increase exercise intensity especially over 65% of vo2max you will you more ?
Muscle glycogen
There are EXPONENTIAL INCREMENTS in muscle ___________ and ___________ as functions of relative exercise intensity
Glycolysis and glycogenolysis
There is a MULTI COMPONENT RESPONSE of ____________ and ____________ with different intensities of exercise
Plasma FFA and triglycerides utilization
The maximal muscle triglyceride utilization occurs at _____ % of Vo2max
65 %
FFA oxidation is predicted to reach minimal values as _______ is approached
Vo2max
Duration and substrate utilization
120 minutes at 25% vo2max
What is used
Long duration low intensity
No use of glycogen stores
Fats dominate especially plasma FFA (blood borne)
Duration and substrate utilization
120 minutes at 65% vo2max
What is used
At the beginning use muscle glycogen the most but at the end use plasma FFA the most to compensate
Muscle triglycerides get repeated over time and same with muscle glycogen
What happens to pyruvate levels in a carb fed state
Increased blood lactate, blood glucose and pyruvate levels implying more glycolysis
Glycogen content was higher in….?
Carb diet not mix diet or fat protein diet
When comparing diets who could cycle the longest
Protein fat diet, mixed, carbs
Longest to shortest
Carb, mixed, protein + fat
Cycling time was correlated with what
Initial glycogen content
Glycogen content of the working muscle is a determinant of what
Of the capacity to perform long and heavy exercise
What was the effect of fat + protein diet after exhaustive work
What about carbohydrate diet ?
Did not synthesize the muscles glycogen content to more than 30% of the initial value
Raised the concentration to far above normal range
What is carb loading
Elevating pre exercise muscle glycogen content above normal resting values
Carb loading
When does it have effects and no effects
Has effects in endurance events lasting more then 90 minutes
- can postpone fatigues be 20%
Exhaustion usually coincides with critically low muscle glycogen
Has NO effect
On high intensity exercise lasting less than 5 min and/or on moderate-low intensity exercise lasting. 60-90 mins
- in such exercise substantial quantities of glycogen remain in the working muscle at the end of exercise
