Chapter 5 (energy) Flashcards
How do you measure indirect calorimetry? what values are attained from the machine and how are they converted to acquire Co2 and oxygen production?
From the machine measurement you will be provided with total expired air and the fraction of co2 and oxygen in it. O2 and Co2 fractions in inspired air are known fractions and the haldane transformation solves the missing piece of the puzzle. Since nitrogen concentrations do not change you can use that to determine the volume of inspired air.
what is RER? what does it tell me? what is it for carbohydrate v.s fat metabolism?
RER is Co2 produced divided by oxygen utilized. Carbs is usually 1.0 and fats is usually .7. Calculating the number will tell you what percentage of fats v.s carbs are being used for energy.
what is the average RER?
.8 or .3 ml.min
Limitations of indirect calorimetry?
can only be used during aerobic activites. does not include protein. Can be off sometimes bc byproducts of energy metabolsm release co2 that adds to total expired air. This co2 is not being used by the muscle but the equation will indicate it is.
define metabolic rate?
rate at which body is using energy
1 L of oxygen equals how many kcals?
5 kcals
Difference between basal metabolic rate and resting metabolic rate?
both indicate the energy expended when at rest. Resting metabolic rate has less requirments so it will be used more often.
What is a big factor in basal metabolic rate?
fat free mass. women will have a lower rate bc they have less fat free mass
relationship between basal metabolic rate and Vo2
the volume of O2 measured will indicate how much oxygen is being consumed by the body which will indicate how much substrate is being used by the body for energy. This can then be converted to kcals which will tell you how many kcals the body is using during any activity
Describe the “slow component”
It is when Vo2 increases after body has surpassed lactate threshold. This happens because the bodys main fibers are fatigued and the body has to rely on less efficient fibers. Forces more energy to be used since the fibers are less efficient
Describe VO2 drift?
It is when VO2 increases below lactate threshold but when exercise intensity is long. This happens because the main type II fibers are tired and it has to use IIx. (less efficient) could also happen bc the rate of breathing increases (more O2 going in to be used). breathing harder for more air
What is VO2 max?
the max amount of oxygen your body can take up before a plateu occurs. It is a good indicator or aerobic fitness not necessarily performance. This is hard to measure bc muscles will give up before you can reach limit
what is VO2 peak?
Max amount of vo2 taken up during an exercise. can be seen when intensity increases no longer correspond with oxygen uptake increase
What makes a good endurance runner?
they can use opperate using a higher percentage of VO2 max for a longer time
Difference between absolute and relative VO2 consumption?
relative is more specific to body type L/min v.s ml/kg/min
what does MET measure?
how much energy you are using compared to rest. 1 met = 3.5 ml/kg/min.
How does anaerobic metabolism affect measurements?
you can not seperate the two. You are never using 100% of either system.
what are two ways to estimate anaerboic metabolism contributions?
lactate threshold and estimated post-exercise oxygen consumption
describe EPOC?
at the begining of the exercise you will be using anaerobic metabolism. Your body will be in an oxygen deficit. This deficit will be made up at the end of exercise. You can measure it by determining how much extra oxygen you are consuming (heavy breathing) compared to normal after exercise