Chapter 13: Physiology of Training: Effects of Aerobic and Anaerobic Training Flashcards
Overload
training effect occurs when a physiological system is exercised at a level beyond which it is normally accustomed
Specificity
Training effect is specific to:
- Muscle fibers recruited during exercise
- Energy system involved (aerobic vs anaerobic)
- Velocity of contraction
- Type of contraction (eccentric, concentric, isometric)
Reversibility
Gains are lost when overload is removed
Training to increase VO2 max
- large muscle groups
- dynamic activity
- 20-60 min
- more or equal to 3 times per week
- greater than or equal to 50% VO2 max
What is the average expected increase in VO2 max after 2-3 months of endurance training?
15-20%
Those with high initial VO2 max will have how much of an increase?
as low as 2-3%
requires higher intensity training (>70% VO2 max)
Those with low initial VO2 max will have how much of an increase?
as high as 50%
requires relatively low intensity training (40-50% VO2 max)
How much of VO2 max is determined by genetics in sedentary adults?
50% of VO2 max
Genetics play a key role in determining…
the training response
Large variations in training adaptations reveal that heritability of training adaptations is approximately
47%
Fick equation
defines VO2
VO2= maximal cardiac output x a-vO2 difference
Differences in VO2 max between individuals is primarily due to
differences in SV max
What is the dominant factor in increasing VO2 max during short duration training?
Increase in stroke volume
how long is short duration training?
approximately 4 months
how long is longer duration training?
approximately 28 months
Research reveals that in untrained subjects, relatively short durations of endurance training increases both ____ and _____, but does not significantly increase the ______
VO2 max; Maximal Cardiac Output; Maximal a-vO2 difference
Following short duration training, all of the training induced improvement in VO2 max is due to
increases in maximal cardiac output
Longer duration of training increases VO2 max by
increasing both maximal cardiac output and the maximal a-vO2 difference
Following both long term and short term duration endurance training, the exercise-induced increase in maximal cardiac output is entirely due to
stroke volume
– maximal HR either remains constant or slightly decreases
Stroke volume
SV= EDV- ESV
how much blood was ejected= how much blood is in the ventricle when filled - how much blood is in the ventricle after contraction
What increases maximal stroke volume?
- an increase in end diastolic volume (preload)
- an increase in contractility
- a decrease in total peripheral resistance (afterload)
Contractility
The strength of contraction
Total peripheral resistance
“afterload”
- The resistance of blood flow
- the pressure which the ventricle pushes against as it tries to push blood into the aorta
What increases Preload (EDV)?
- increase in plasma volume
- increase filling time and venous return
- increase in ventricular volume
What decreases Afterload (total peripheral resistance)?
- decrease in sympathetic vasoconstriction
- increase in maximal muscle blood flow
6 day training program (2hr/day at 65% VO2 max) resulted in…
7% increase in VO2 max due to:
- 11% increase in plasma volume
- 10% increase in stroke volume
Increase in a-vO2 difference in response to endurance training is due to
increased O2 extraction from the blood
Improved ability of the muscle to extract oxygen from the blood is due to
- increased capillary density
- increased mitochondrial number
Increased Capillary density
- slows rate of blood flow to allow time for O2 diffusion to take place (aka increases muscle blood flow)
- improves ability of the muscle to extract oxygen from the blood
- decreases diffusion distance to the mitochondria
The ability to continue prolonged, submaximal work is dependent on the
maintenance of homeostasis during the activity
Maintenance of homeostasis in response to endurance training is reached by:
- more rapid transition from rest to steady-state
- reduced reliance on liver and muscle glycogen stores
- cardiovascular and thermoregulatory adaptations
Endurance training result in a fast-to-slow shift in muscle fiber type… what does this mean?
- reduction in fast myosin and increase in slow myosin
- this means you can perform more work with less ATP use (aka increased mechanical efficiency, which can improve endurance performances)