Chapter 6-Aerobic training adaptations Flashcards
Cardiac output
amount of blood pumped by the heart in liters/min
stroke volume x HR
stroke volume
quantity of blood ejected with each beat
regulated by end-diastolic volume (volume of blood available to be pumped by the left ventricle at the end of filling and the action of catecholamines (epinephrine and norepinephrine) which produce a more forceful ventricular contraction
Frank-Starling mechanism
with increased volume, myocardial fibers become more stretched than at rest, resulting in increased force of systolic ejection and greater cardiac emptying
Oxygen uptake
amount of oxygen consumed by the body’s tissues
maximal oxygen uptake
greatest amount of oxygen that can be used at the cellular level for the entire body
Fick equation
VO2 = Q x a-vO2 difference
VO2 = HR x stroke volume x a-vO2 difference
relationship of cardiac output, oxygen uptake and arteriovenous oxygen difference
Acute aerobic exercise results in…
increased cardiac output, stroke volume, heart rate, oxygen uptake, systolic blood pressure and blood flow to active muscles and decreased diastolic blood pressure
Respiratory responses to aerobic exercise
large amounts of oxygen diffuse from the capillaries into the tissues, increased levels of carbon dioxide move from the blood into the alveoli and minute ventilation increases to maintain appropriate alveolar concentrations of gases
Cardiovascular adaptations to aerobic training
increased maximal cardiac output, increased stroke volume, reduced HR at rest and submaximal exercise, muscle fiber capillary density increases supporting delivery of oxygen and removal of carbon dioxide
Neural adaptations to aerobic training
play a significant role in the early stages of training
efficiency is increased and fatigue of the contractile mechanism is delayed
improved aerobic performance may result in a rotation of neural activity among synergists
Muscular adaptations to aerobic training
increased aerobic capacity of trained musculature
athlete can exercise at a greater relative intensity of a higher maximal aerobic power
this adaptation occurs as a result of glycogen sparing and increased fat utilization
OBLA occurs at higher percentage of trained aerobic capacity
increase in size and number of mitochondria (organelles responsible for producing ATP via oxidation of glycogen and free fatty acids)
increased myoglobin (protein that transports oxygen)
Bone and connective tissue adaptations
some success in improving bone mass when
involves more intense activities like running and high-intensity aerobics
activity is more intense than daily activities to exceed the minimum threshold
Endocrine adaptations
testosterone, insulin, IGF and growth hormone affect the integrity of the muscle, bone and connective tissue and maintain metabolism in a normal range
increases in hormonal circulation and changes at the receptor level are specific responses to aerobic exercise
Aerobic endurance training results in…
reduced body fat, increased maximal oxygen uptake, increased running economy, increased respiratory capacity, lower blood lactate concentrations at submaximal exercise, increased mitochondrial and capillary densities and improved enzyme activity
Adjustments to prolonged altitude exposure
increased formation of hemoglobin (5-15%)
increased red blood cells (30-50%)
increased diffusing capacity of oxygen through pulmonary membranes
maintenance of acid/base balance of body fluids by renal excretion and hyperventilation
increased capillarization
Blood doping
practice of artificially increasing red blood cell mass as a means to improve athletic performance
can be accomplished through infusion of one’s own red blood cells, those of another or administration of erythropoietin (EPO) to stimulate the production of red blood cell mass
Upper limits influence adapations
genetic potential influences absolute magnitude of gains
current training status also influences it as the closer you approach your upper limits, the smaller your gains
Age and sex
when women and men are matched by age, aerobic power values for women range from 73-85% of men
may be caused by women’s higher percentage of body fat and lower blood hemoglobin values and men’s larger heart size and blood volume
Markers of aerobic overtraining
decreased performance
decreased % body fat
decreased maximal oxygen uptake
altered blood pressure
increased muscle soreness
decreased muscle glycogen
altered resting HR and decreased HR variability
increased submaximal exercise HR
decreased lactate
increased creatine kinase
altered cortisol concentration
decreased total testosterone concentration
decreased ratio of total and free testosterone to cortisol
decreased ratio of total testosterone to sex hormone-binding globulin
decreased sympathetic tone
increased sympathetic stress response
change in mood states
decreased performance in psychomotor speed tests
17 yr old high school cross country runner has been training aerobically for 6 months in preparation for the upcoming season. adaptations in the muscles will include
hypertrophy of Type I fibers
the amount of blood ejected from the left ventricle during each beat
stroke volume
normally increase during aerobic exercise
end-diastolic volume
cardiac contractility
cardiac output
diastolic blood pressure DOES NOT increase
Mean arterial pressure
average blood pressure throughout the cardiac cycle
primary training adaptations of elite aerobically trained athletes include
increased maximal oxygen uptake
decreased blood lactate concentration
increased running economy
