Chapter 6 - Adaptations to Aerobic Endurance Training Programs Flashcards
Acute Cardiovascular Responses to Aerobic Exercise
Cardiac Output: From rest to steady-state aerobic exercise, cardiac output initially increases rapidly, then more gradually, and subsequently reaches a plateau.
With max exercise, cardiac output may increase to four times the resting level.
Cardiac Output
The amount of blood pumped by the heart in liters per minute.
Q = SV x HR
Stroke Volume - Acute Cardiovascular Responses
Quantity of blood ejected with each beat.
End-diastolic volume is significantly increased.
At onset of exercise, sympathetic stimulation increases SV.
Heart Rate - Acute Cardiovascular Responses
Increases linearly with increases in intensity.
Oxygen Uptake - Acute Cardiovascular Responses
O2 uptake increases during acute bout of aerobic exercise and its directly related to the mass of exercising muscle, metabolic efficient, and exercise intensity.
Maximal O2 Uptake
Greatest amount of O2 that can be used at cellular level for entire body.
Resting O2 Uptake
Estimated at 3.5 mL of O2 per kg-BW/minute. This value is defined as 1 metabolic equivalent (MET).
Systolic and Diastolic Blood Pressure
Systolic BP: estimates the pressure exerted against the arterial walls as blood is forcefully ejected during ventricular contraction.
Diastolic BP: used to estimate the pressure exerted against the arterial walls when no blood is being forcefully ejected through the vessels.
Control of Local Circulation - Acute Cardiovascular Responses
During aerobic exercise, blood flow to active muscles is considerably increased by the dilation of local arterioles.
At the same time, blood flow too other organ systems is reduced by constriction of the arterioles.
General Consensus of Acute Responses to Aerobic Exercise
Results in increased cardiac output, SV, HR, O2 uptake, Systolic BP, and blood flow to active muscles.
Decreased in diastolic pressure.
Respiratory Responses
Aerobic Exercise, as compared to other types of exercise, provides for the greatest impact on both O2 uptake and CO2 production.
During aerobic exercise, large amounts of O2 diffuse from the capillaries into tissues, increased levels of CO2 move from blood into the alveoli, and minute ventilation increases to maintain appropriate alveolar concentrations of the gases.
Gas Responses
During high-intensity aerobic exercise, the pressure gradients of O2 and CO2 cause the movement of gases across cell membranes (diffusion).
The diffusing capacities of O2 and CO2 increase dramatically with exercise, which facilitates their exchange.
Diffusion
Movement of O2 and CO2 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.
Blood Transport of Gases and Metabolic By-Products
Most O2 in blood is carried by hemoglobin.
Most CO2 removal is from its combination with H2O and delivery to the lungs in the form of bicarbonate.
During low- to moderate-intensity exercise, enough O2 is available that lactic acid doesn’t accumulate because the removal rate is greater than or equal to the production rate.
Aerobic exercise level at which lactic acid (converted to blood lactate at this point) begins to show an increase (onset blood lactate accumulation; OBLA).
Physiological Adaptations to Aerobic Endurance Training - PERFORMANCE
Muscle Strength Muscle Endurance Aerobic Power Maximal Rate of Force Production Vertical Jump Anaerobic Power Sprint Speed
Muscle Strength: No change.
Muscle Endurance: Increase for low power output.
Aerobic Power: Increases.
Maximal Rate of Force Production: No change or decreases.
Vertical Jump: Ability unchanged.
Anaerobic Power: No change.
Sprint Speed: No change for improves slightly.
Physiological Adaptations to Aerobic Endurance Training - MUSCLE FIBERS
Fiber Size Capillary Density Mitochondrial Density Myofibrillar Packing Density and Volume Cytoplasmic Density Myosin Heavy Chain Protein
Fiber Size: No change or improves slightly.
Capillary Density: Increases.
Mitochondrial Density: Increases.
Myofibrillar Packing Density and Volume: No changes.
Cytoplasmic Density: No change.
Myosin Heavy Chain Protein: No change.