Chapter Six: Adaptations to Aerobic Endurance Training Programs Flashcards
Acute Responses to Aerobic Exercises: Cardiovascular Responses: Cardiac Output
- The amount of blood pumped by the heart in liters per minute
- Initially increases rapidly then more gradually, then plateaus
- 5L/min up to 20-22L/min
Acute Responses to Aerobic Exercises: Cardiovascular Responses: Stroke Volume
- Quantity of blood ejected with each beat
- Begins to increase at onset of exercise and continues to increase until 40-50% of maximal oxygen uptake
Acute Responses to Aerobic Exercises: Cardiovascular Responses: Stroke Volume: Regulation: End Diastolic Volume
- The volume of blood left to be pumped by the left ventricle at the end of the filling phase (diastole)
Acute Responses to Aerobic Exercises: Cardiovascular Responses: Stroke Volume: Regulation: Catecholamines
- Epinephrine and norepinephrine produce a more forceful ventricular contraction.
Acute Responses to Aerobic Exercises: Cardiovascular Responses: Stroke Volume: Venous Return
- The amount of blood returning to the heart
- Increased via various mechanisms during exercise
- Increased venous return contributes to increased end diastolic volume
Acute Responses to Aerobic Exercises: Cardiovascular Responses: Stroke Volume: Frank Starling Mechanism
- Increased venous return contributes to increased end diastolic volume
- Increased end diastolic volume contributes to increased elastic stretch and contraction by myocardial fibers
- Increased stretch and contraction via myocardial fibers increase in force of systolic ejection and greater cardiac emptying
Acute Responses to Aerobic Exercises: Cardiovascular Responses: Stroke Volume: Frank Starling Mechanism
- Force of contraction is a function of the length of the fibers of the muscle wall
Acute Responses to Aerobic Exercises: Cardiovascular Responses: Stroke Volume: Ejection Fraction
- An increase in end diastolic volume ejected from the heart
Acute Responses to Aerobic Exercises: Cardiovascular Responses: Heart Rate
- Heart Rate increases prior to exercise
- Heart Rate increases linearly with exercise intensity
Acute Responses to Aerobic Exercises: Oxygen Uptake
- The amount of oxygen consumed by the bodies tissues
- The amount of oxygen consumed is directly related to the mass of exercises muscle, metabolic efficiency, and exercise intensity
- Increased metabolic efficiency contributes to increased oxygen uptake at higher intensities.
Acute Responses to Aerobic Exercises: Maximal Oxygen Uptake
- The greatest amount of oxygen that can be used at the cellular level
- 25 to 80ml/kg/min
Acute Responses to Aerobic Exercises: Metabolic Equivalent (MET)
- 3.5 ml of Oxygen per kilogram of body weight
Acute Responses to Aerobic Exercises: Oxygen Uptake: Fick Equation
- Relationship of cardiac output, Oxygen uptake, and arteriovenous oxygen difference
Acute Responses to Aerobic Exercises: Aterio-venous Difference
- The difference in the oxygen content between arterial and venous blood
Acute Responses to Aerobic Exercises: Blood Pressure: Systolic Blood Pressure
- The pressure exerted against the arterial walls as blood is forcefully ejected during ventricular contraction
Acute Responses to Aerobic Exercises: Blood Pressure: Rate Pressure Product
- Equation used to determine the work done by the heart/myocardial oxygen consumption
- Rate Pressure Product=Heart Rate X Systolic Blood Pressure
Acute Responses to Aerobic Exercises: Blood Pressure: Diastolic Blood Pressure
- The pressure exerted against the arterial walls when no blood is being forcefully ejected through the vessels
- Provides an indication of peripheral resistance and can decrease with aerobic exercise
Acute Responses to Aerobic Exercises: Blood Pressure: Pressure Throughout Circulation
- Highest in Aorta
- Decreases to nearly 0 by termination at the vena cava
Acute Responses to Aerobic Exercises: Blood Pressure: Mean Arterial Pressure
- The Average blood pressure throughout the cardiac cycle
- ((SBP-DBP)/3)+DBP
Acute Responses to Aerobic Exercises: Blood Pressure: Normal Resting Values
- Systolic BP=110-139
- Diastolic BP=60-89
Acute Responses to Aerobic Exercises: Blood Pressure: Normal Active Values
- Systolic can rise to as much as 220-260
- Diastolic stays the same or slightly decreases
Acute Responses to Aerobic Exercises: Control of Local Circulation
- Blood flow is primarily controlled via vasoconstriction and vasodilation
- Arteriole dilation and constriction controls blood flow
- At rest 15-20% of blood flow is distributed to skeletal muscles
- With vigorous exercise this may rise to as much as 90%
Acute Responses to Aerobic Exercises: Respiratory Responses: Minute Ventilation
- The volume of air breathed per minute
- Can increase to 90-150L/min with strenuous activity
Acute Responses to Aerobic Exercises: Respiratory Responses: Changes to Various Respiratory Parameters with Exercise: Breaths Per-Minute
- At rest breathing frequency=12-15 BPM
- With strenuous aerobic exercise BPM can increase to 35-45 BPM
Acute Responses to Aerobic Exercises: Respiratory Responses: Changes to Various Respiratory Parameters with Exercise: Tidal Volume
- The amount of air inhaled and exhaled with each breath
- Resting values of (0.4 to 1L)
- With strenuous aerobic activity can increase to 3L
Acute Responses to Aerobic Exercises: Respiratory Responses: During Low to Moderate Intensity Exercise
- Ventilation is Directly Associated with both increased oxygen uptake and carbon dioxide production
Acute Responses to Aerobic Exercises: Respiratory Responses: During Low to Moderate Intensity Exercise: Ventilatory Equivalent
- The ratio of minute ventilation to oxygen uptake
- Ranges between 20-25L of air per oxygen consumed
Acute Responses to Aerobic Exercises: Respiratory Responses: During Intense Exercise
- Breathing frequency takes on a greater role
- At this level minute ventilation rises and parallels the abrupt rise in blood lactate
- At this level ventilatory equivalent may increase to 35-40L of air per liter of oxygen
Acute Responses to Aerobic Exercises: Alveoli
- The functional unit of the pulmonary system where gas exchange occurs
Acute Responses to Aerobic Exercises: Anatomical Dead Space
- Areas of the respiratory system where gas exchange does not take place
- Approx 150 mL in young adults
Acute Responses to Aerobic Exercises: Physiologic Dead Space
- Non-functional alveoli
- Nearly negligible in healthy adults
Gas Responses: Diffusion
- The movement of oxygen and carbon dioxide across a cell membrane and is a function of the concentration of each gas and the resulting partial pressure exerted by the molecular motion of each gas
- Results from the movement of gasses from high concentration to low concentration
Gas Responses: Partial Pressure of Oxygen
- Starts around 100 mmHg and drops to 40mmHg
Gas Responses: Partial Pressure of CO2
- 46mmHg
Gas Responses: Partial Pressure Changes with Intense Aerobic Exercise
- Oxygen 3mmHg
- Carbon Dioxide 90 mmHg
- The diffusion capacity of both gases increases
Blood Transport of Gases and Metabolic By-Products: Oxygen Carrying Capacity
- Oxygen is carried in plasma or hemoglobin
- Plasma has limited carrying capacity to about 3ml of Oxygen per liter of plasma
Blood Transport of Gases and Metabolic By-Products: Oxygen Carrying Capacity: Hemoglobin
- Majority of oxygen is carried by hemoglobin
- Men have 15-16g of hemoglobin per 100ml of blood
- Women have 14g of hemoglobin per 100 ml of blood
- One gram of hemoglobin can carry 1.34 ml of oxygen
- 100ml of blood can carry 20ml of oxygen
Blood Transport of Gases and Metabolic By-Products: Carbon Dioxide Carrying Capacity
- Around 70% of carbon dioxide is removed from circulation in combination with water and delivery to the lungs in the form of bicarbonate
Blood Transport of Gases and Metabolic By-Products: Carbon Dioxide Carrying Capacity: Steps
- Carbon dioxide in solution combines with water in the red blood cells to form carbonic acid
- Carbonic Anhydrase speeds up this process
- Carbonic acid is broken down into hydrogen ions and bicarbonate ions
- Hydrogen ions combine with hemoglobin which helps to maintain pH
- Bicarbonate ions diffuse from the red blood cells to the plasma
- While chloride ions diffuse into the blood cells to replace them
Blood Transport of Gases and Metabolic By-Products: Lactic Acid
- Low to moderate intensity oxygen is sufficient to buffer lactic acid accumulation
- Intense activity causes lactic acid to accumulate due to reduced buffering
- The point at which lactic acid accumulation begins to out pace oxygen buffering is termed the onset of blood lactate accumulation or OBLA
Chronic Adaptations to Aerobic Exercise: Cardiovascular Adaptations
- Increased maximal cardiac output
- Increased stroke volume
- reduced heart rate at rest
- Increased muscle fiber capillary density
Chronic Adaptations to Aerobic Exercise: Cardiovascular Adaptations: Factors effecting maximal oxygen uptake
- Slower discharge of SA node
- Increased stroke volume
Chronic Adaptations to Aerobic Exercise: Cardiovascular Adaptations: Bradycardia
- Resting heart rate below 60
Chronic Adaptations to Aerobic Exercise: Cardiovascular Adaptations: Increased MaximalCardiac Output is due to
- Increased stroke volume
Chronic Adaptations to Aerobic Exercise: Cardiovascular Adaptations: Other adaptions to Aerobic Training
- Reduced Heart Rate in response to a given submaximal workload
- Heart rate increases more slowly in trained individuals
Chronic Adaptations to Aerobic Exercise: Cardiovascular Adaptations: Changes to the Left Ventricle
- Increased wall thickness
- Increased strength of contraction
Chronic Adaptations to Aerobic Exercise: Cardiovascular Adaptations: Changes to the Left Ventricle Cause
- Increased stroke volume
Chronic Adaptations to Aerobic Exercise: Cardiovascular Adaptations: Changes to Capillaries
- Increased capillary density
Chronic Adaptations to Aerobic Exercise: Cardiovascular Adaptations: Changes to Capillaries Cause
- Decreased diffusion distance of oxygen
Chronic Adaptations to Aerobic Exercise: Respiratory Adaptations
- Ventilation changes in response to specific training adaptations (Example: Lower extremity exercises causes adaptations to ventilation with lower extremity exercise but not upper extremity exercises)
- Increased tidal volume and breathing frequency with maximal exercises
- Reduced breathing frequency and increased tidal volume with sub-maximal exercises
- Alterations of respiratory function are typically a result of local, neural, or chemical adaptations
Chronic Adaptations to Aerobic Exercise: Neural Adaptations
- Improved neural efficiency causes rotation of synergists. Synergetic muscles alternate between active and inactive with locomotion to lower energy expenditure
Chronic Adaptations to Aerobic Exercise: Muscular Adaptations
- Improved aerobic capacity of of trained musculature allows for improved use of oxygen and improved ability to compete at a higher aerobic power
- Glycogen sparing takes place as musculature utilizes fat as a primary energy source
- OBLA occurs at a higher percentage of the trained athletes aerobic capacity
- Increased myoglobin content and mitochondrial size and number allows for improved oxygen extraction.
Chronic Adaptations to Aerobic Exercise: Muscular Adaptations: Type I and Type II Muscle Fiber Changes
- Type I and Type II fibers both contribute to aerobic output, however, type II fibers must be trained with slightly higher intensity to contribute to endurance training
- Type I muscle fibers will selectively hypertrophy
- Reduced glycolytic enzyme concentration reduces the overall mass of the type II muscle fibers
- Type IIx fibers will convert to type IIa fibers.
- Type IIa fibers have a greater aerobic capacity contributing to aerobic endurance events
Chronic Adaptations to Aerobic Exercise: Bone Adaptations:
- High intensity interval training can be used to create repetitive movements that stimulate bone growth and achieve the improvements associated with aerobic activity
- Weight bearing activities increase bone density
- Studies are mixed on the impact of cardio on cartilage but generally show a positive impact on repetitive weight bearing activities on cartilage thickness
Chronic Adaptations to Aerobic Exercise: Endocrine Adaptations
- Increases in hormonal circulation and changes to receptor number and turnover rate are impacted by aerobic exercise
- High intensity aerobic training augments the absolute secretion rates of hormones in response to maximal exercise
- Trained athletes increased hormonal response to high intensity aerobic activity augment the athletes ability to sustain high intensity activity
- When intensity is very high and duration is very short only changes in peripheral blood hormone concentrations occur (epinephrine and norepinephrine)
Adaptations to Aerobic Endurance Training
- Aerobic metabolism plays a vital role in sporting activities, a proper mixture of aerobic and anaerobic training to support the proper metabolic metabolism of the activity
- Aerobic training can increase maximal oxygen uptake to improve aerobic power. After maximal oxygen uptake is reached further adaptation are achieved via improved efficiency and lactate threshold
- Studies show reduced rest intervals between bouts of aerobic training improved aerobic power better than long rest intervals
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training: Altitude
- At altitudes greater tan 3900 feet acute physiologic changes begin to occur to account for the reduced partial pressure of oxygen in the atmosphere
- Increased pulmonary ventilation occurs acutely
- Increased tidal volume occurs chronically
- Increased cardiac output and heart rate occurs acutely
- Stroke volume is constant or slightly reduced
- Increased red blood cell count occurs chronically
- Increased hemoglobin
- Increased diffusion capacity of oxygen through pulmonary membranes
- Maintenance of acid base balance via kidney secretion of HCO3-
- Increased capillarization
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training: Hyperoxic Breathing
- Studies are a mixed bag on the effectiveness of hyperoxic breathing
- Theoretically could increase the amount of oxygen carried by the blood and could therefore increase the amount of blood going to working muscles
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training: Smoking: Negative Impacts
- Increased airway resistance
- Paralysis of cilia
- Carbon monoxide a component of many smoking products has a higher affinity for hemoglobin than oxygen. Thus if high levels of Carbon monoxide bind to hemoglobin this can decrease the amount of oxygen available to working muscles.
- Increased heart rate and blood pressure to accommodate for decreased oxygen carrying capacity
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training: Genetic Potential
- An athletes genetic potential contributes to their potential gain from training
- As the athlete approaches their genetic potential increases in ability become smaller
- In high level competition the small gains from working as close to ones genetic potential can be important differentiators for performance
Overtraining: Definition
- A process marked by over reaching, in the short term, followed by functional over-reaching, followed by non functional over-reaching followed by over training syndrome
Overtraining: Cardiovascular Responses
- Resting heart rate can be either increased or decreased in association with OTS
- Reduction in parasympathetic input and increased sympathetic input
- Heart rate response to both maximal and submaximal exercise can be impacted
- Diastolic blood pressure can be impacted while systolic blood pressure may not be
Overtraining: Biomechanical Responses
- Increased creatine kinase indicating muscle damage
- Lactate concentrations either decrease or stay the same
- Blood lipids stay the same
- Glycogen decreases
Overtraining: Endocrine Responses
- Changes to hormones may reflect training volumes
- Testosterone and cortisol alterations may indicate overtraining with decreases of the testosterone to cortisol ratio
- Catecholamines are more responsive to alterations in training and will increase in response to OTS
Overtraining: Strategies for prevention of overtraining syndrome
- Adequate recovery
- Adequate sleep
- Adequate nutrition
Detraining
- A partial or complete loss in training induced adaptations in response to an insufficient training stimulus
Tapering
- A planned reduction in the volume of training that occurs before an athletic competition designed to enhance athletic performance
