Chapter 6 - Adaptations To Aerobic Training Flashcards
What are acute adaptations to aerobic training? Decreases
Peripheral resistance Splanchnic blood flow Plasma volume Blood pH Insulin Cortisol (with low to moderate intensity)
What is formula for aerobic cardiac output?
Output = HR x stroke volume (L/beat)
When does stroke volume increase to max levels?
At 40 to 60% of max oxygen consumption
What is the Frank-Starling mechanism?
Stroke volume of the heart increases proportionally to the volume of blood filling the heart
How much does peripheral resistance decrease?
50 to 60%
Due to vasodilation
How much does BP increase?
Mean arterial pressure = DBP + (.333 x (SBP - DBP))
Or
= Q x TPR
What happens to coronary vasculature?
Vasodilates as a result of the increased oxygen demand placed on heart muscle
Rate-pressure product indicates how much oxygen heart needs
RPP = HR x SBP
What is pulmonary minute ventilation?
Product of breathing rate and tidal volume in one minute
Increases during exercise
PMV (L/min) = BR x TV
What is respiratory quotient?
Ratio of volume of CO2 production to oxygen consumption at cellular level
Also called respiratory exchange ratio
RQ = VCO2 / VO2
When is RQ used?
To estimate proportion of fat and carb utilization during rest and exercise
RQ is .82 at rest
As intensity increases, RA and RER approach 1.0 and proportion of energy derived from carbs increases
RER can increase to greater than 1 due to hyperventilization
What is arteriovenous oxygen difference?
Difference between amount to oxygen in arterial and mixed venous blood
Normal values for resting arterial and venous oxygen per 100 ml of blood are 20 and 14 ml
Normal resting a-vO2 difference is 6 ml of O2 per 100 ml blood
Can reach 18ml oxygen per 100 ml at VO2 max
What is Fick equation?
Volume of O2 consumed
Product of Q x a-vO2 difference
Which enzyme is produced when metabolism increases?
Lactate, decreasing pH (raising acidity in blood)
What do catecholamines do?
Facilitate responses to enhance delivery of O2 and nutrients and removal of waste
Involve pancreas, adrenal cortex, adrenal medulla
What does pancreas release?
Insulin, glucagon
Glucagon stimulates increase in plasma glucose concentration
Insulin facilitates glucose transport into cells
What does adrenal cortex release?
Cortisol
Where does growth hormone come from?
Anterior pituitary
What are catecholamines?
Epinephrine and norepinephrine
Fight or flight hormones
Released from adrenal medulla
Released during exercise because it’s a stressor
What is decreased in aerobic exercise maximal output?
Max heart rate
Cardiac output remains unchanged at rest
Either unchanged or slightly decreased at fixed submaximal exercise intensity
At rest and any fixed submax intensity, adaptations include decrease in heart rate and increase in stroke volume
Reduction in heart rate may take 10 weeks
What happens to heart?
Left ventricular cavity enlargement
Increased myocardial wall thickness
Training-induced bradycardia slower heart rate
Improved cardiac contractile function are major factors accounting for chronic stroke volume increases
Increase in plasma volume (24 hours) and red blood cell volume (weeks)
Hyptertension people get lower BP than ppl with normal BP
Immediate lowering for both lasting 22 hours
Increase in density of capillaries per unit of muscle
Increases in arteriole densities, diameters
Which type to aerobic recruit?
Type 1
No change after training
Type 2 no changes
How does muscle change?
Increased capillary supply, mitochondrial density, higher oxidative enzyme activity
Capillaries increase in number
Metabolic adaptations?
Higher reliance on fat
Lower carb use during submaximal exercise
Increase in lactate threshold and max oxygen consumption
Threshold for lactate accumulation occurs at higher percentage of trained person’s capacity
Endurance athlete may have lactate threshold in range of 80 to 90% of aerobic capacity
Resting oxygen consumption does not change
How does endocrine adapt?
Reduction in epinephrine, norep, glucagon, cortisol, GH in person who performs same absolute level of submax exercise posttraining as pretraining
Insulin levels decrease less in trained person during submax
Acute improves insulin sensitivity and decreases glucose in type 2 diabetes ppl until 72 hours after
Bones?
Plyometrics, resistance training, weight bearing aerobic activity benefits
Body composition?
Moderate activity of less than 150 minutes per week minimal weight loss
Greater than 150 minutes 4.4-6.6 lbs
Moderate for 225 to 420 minutes 11 to 16.5 lbs
Reduces fat while minimal effect on fat-free mass
No change in power, strength, speed
How does sex affect?
Females have lower cardiac output, stroke volume, oxygen consumption at 50% VO2 max
How does age affect?
Females reach highest VO2 max between 12 and 15
Males reach 17 to 21
In five middle-aged men, 100% of age-related decline in aerobic power over 30 years reversed by 6 mos endurance training
