Adaptations To Aerobic Endurance Training Programs Flashcards
What is the primary role of the CV system during exercise?
- Deliver O2/nutrients to work tissue
- Remove metabolites and waste
Maintains a constant supply of energy to continue activity
What is Cardiac output (Q)?
The amount of blood pumped by the heart in liters per minute
Stroke volume (SV)
The quantity of blood ejected with each beat
Heart Rate (HR)
Hearts pumping per min
What is the equation for cardiac output?
Q = (SV × HR)
HR increases linearly w/ increases in intensity
True or false
True
Cardiac output is about?
With maximal exercise, Q may increase to 4x the resting level
5L/min to a max of 20 -22L/min
What is EDV?
Vol of blood is available to be pumped by the left ventricle at the end of the filling phase or diastolic
During Acute Cv responses to Aerobic exercise
Stroke volume increase until about 40% VO2max
More mass of muscle= higher vo2
More metabolically efficient = less vo2
Higher ex ints = higher vo2
What regulates SV?
Frank-Starling mechanism
VO2 Max
-Maximal oxygen uptake
-It’s not the same as VO2
-Reproducible measure of the capacity of the CV system to deliver oxygenated blood to a large muscle mass involved in dynamic work
How to improve VO2 max?
Fick equation
VO2max = Q × a-vO2 diff
Q=deliver CV
a-vO2diff=extraction use of O2
What is the resting oxygen uptake?
Estimated at 3.5 ml of oxygen per kilogram of body weight per minute
Systolic
Pressure exerted against arterial walls as blood forcefully ejects during ventricular contraction.
Diastolic
Pressure exerted against arterial walls when no blood is being forcefully ejected
Mean arterial pressure is?
Avg blood pressure throughout the cardiac cycle.
Map = [(SBP-DBP)/3]+DBP
What is the purpose/goal for redistribution of blood flow?
Only have ~5L of blood to circulate around the body at one time.
The goal is to provide blood to areas that need it and take away from areas that don’t need it
Main areas: stomach, intestine, kidneys
Control of local circulation
Blood flow to active muscles happens by the dilation of local arterioles. While blood flow to the other organs reduce by contric5ion of the arterioles
What is the impact of aerobic exercises on resoiratory responses?
Provides for the greatest impact on both oxygen uptake and carbon dioxide production
Blood transport of gases and metabolic by-products
The aerobic exercise level at which lactic acid
O2 carried via hemoglobin (~20 ml/100 ml blood)
Small amount of O2 dissolved in the plasma
Most CO2 (70%) removal is from its combination with water and delivery to the lungs in the form of bicarbonate (HCO3-)
Small amounts carried via hemoglobin and dissolved
During low- to moderate-intensity exercise, enough O2 is available that lactic acid does not accumulate. (Clearance > production)
Cori cycle > liver for gluconeogenesis
Removal of CO2/Lactate (or H+)
Initial step in reversible reaction is combination of carbon dioxide in a solution of water in the RBC to form carbonic acid. The reaction is normally slow but the enzyme carbonic anhydrase speeds up process. Next it is broken down to a hydrogen ion and bicarbonate ion. Hydrogen ions combine with hemoglobin, which helps to maintain pH of blood. Bicarb ion diffuses from RBC to the plasma in exchange for a chloride ion entering the blood cell.
This system in combination with the respiratory system to help maintain appropriate pH levels, if blood becomes to acidic respiratory rate will increase to rid the body of excess hydrogen ions and if blood becomes to alkaline respiration will decrease in order to increase hydrogen ion concentration
Training Programs and Changes in VO2max
Basic Formula:
Dynamic exercise using large muscle mass
20-60 min per session
3-5 times per week
50-85% of VO2max
Typical Changes:
2-3 months training = 15-20% increase in VO2max
Range: 2-50%
Aerobic endurance training will result in several changes in the cardiovascular function, including increased vo2 max, maximal cardiac output, stroke volume, and a reduced HR at rest and during submaximal exercise. Capillary density will also increase in muscle which means more o2 delivery and more co2 removal.
Chronic CV Adaptations
VO2max = maximal cardiac output X maximal a-vO2 difference
Increases in maximal cardiac output, stroke volume, and fiber capillary density – fiber density decreases diffusible distance which is a good thing!
Increased parasympathetic tone leads to decreases in resting and submaximal exercise heart rates
Most significant change in CV function w/ long-term training is the increase in maximal cardiac output, resulting in an improved SV.
Increase in capillary density will help with removal of heat and metabolic by-products as well as decrease the diffusion distance for oxygen.
Chronic Muscular Adaptations to Aerobic Exercise
One of the fundamental adaptive responses is an increase in the aerobic capacity of the trained musculature.
Allows the athlete to perform a given absolute intensity of exercise with greater ease after aerobic endurance training
Myoglobin is the protein that transports oxygen within the muscle cell
We also see the capacity of the muscle tissue to extract and use oxygen is enhanced.
An increase in bone growth with weight bearing exercises such as running. As long as activity is more intense than daily activity then bone growth will occur.
