Cardiopulmonary System and Response to Exercise Flashcards
P Wave
Atrial depolarization
QRS Complex
Ventricular depolarization
T Wave
Ventricular repolarization
Cardiovascular Function
Deliver oxygen and nutrients Remove CO2 and waste Transport hormones Maintenance of pH balance and clearing of kidneys Prevention of CVD
Anaerobic Threshold
Rise in CO2 disproportionate to rise in OT - can’t clear waste
Resting Respiratory Exchange Ratio
VCO2/VO2
>1 = anaerobic metabolism
1.05-1.09 = max effort
Increase with exercise as CO2 production > O2 consumption
Maximal Oxygen Consumption
Improves 10-30% with training
Greater gains in reconditioned individuals
VO2 Norms
Stroke - 12-15
Active 20 yo - 35-40
Athlete - 90-93
Cardiac Output
@ Rest - 5L/min
Exercise - 20/25L/min
Increases linearly with workload
Up to 50% max capacity due to increase in SV and HR, after 50% due to HR
Stroke Volume
Most important in determining VO2 max
Higher at fixed or submax workload with training
SV Adaptations
Increased wall thickness
Preload
Ability to squeeze
Ejection Fraction
60-70% - healthy
Karvonen
Training range % x (HR max - resting) + HR resting
HR Response to Exercise
Sedentary individuals decrease resting HR 1 bpm/wk
Recovery should drop 12-18 beats within 1st minute
Pulmonary Ventilation
Gas exchange from high to low pressure
Fick’s Law
Amount of gas moves across tissue is proportional to area and inversely related to thickness
Hyperventilation
Increased ventilation increases pH
Ventilation
Matches energy metabolism during steady state by varying VO2 and VE
Respiratory Limitations to Performance
Respiratory muscles use > 15% of total oxygen during exercise (more resistance to fatigue)
Pulmonary ventilation rarely limiting factor due to max exercise
Respiratory Regulation of Acid-Base Balance
Excessive H+ impairs muscle contractility
Therefore, increases respiration allow more CO2 to be transported
AV O2 Difference
Difference between arterial and venous blood oxygen content
Resting - 5 mL/O2/100mL/dL
Exercise - 15 ML/O2/100mL/dL
Increased by greater SV
Blood Volume
Increase with endurance training
Increase due to increased plasma volume (correlated with SV and VO2 max)
High hematocrit (blood doping) - >48%
Blood Flow
Increases with training
Increased capillarization -> increased blood volume
Blood Pressure
Reflects intra-arterial pressure during systole and diastole
Systolic increases with exercise
Low at rest and submax exercise
Mean Arterial Pressure
Cardiac output x Total peripheral resistance
Nervous Control of Blood Pressure
Long-term - kidneys
Short-term - cardiovascular system
Cardiac and pulmonary stretch receptors
HR with Aging
Resting: little change/increase
Lower max HR
Increased LV mass/wall thickness -> ventricle gets smaller
High HR during submax
VO2 with Aging
Decreases (CO and SV)
Decreased BF to muscles
Metabolic with Aging
Decreased insulin sensitivity (inc blood sugar), HDL and increased cholesterol
Increased peripheral vascular resistance
Effect of Training with Aging
All CV can be improved but won’t be as efficient