Chapter 6

stroke volume responses

-EDV is significantly increased -at onset of exercise, sympathetic stimulation increases stroke volume

blood pressure responses

-SBP estimates pressure exerted against arterial walls as blood is forcefully ejected during vbentricular contraction -DBP is used to estiamte pressure exerted against arterial walls when no blood is being forcefully ejected through the vessels

endocrine adaptations

-aerobic exercise leads to increase in hormonal circulation and changes at the receptor level -high intensity aerobic endurance training augments the absolute secretion rat3es of many hormones in response to maximal exercise -trained athletes have blunted responses to submaximal exercise.

respiratory responses

-aerobic exercise provides for the greatest impact on both oxygen uptake and carbon dioxide production, as compared to other types of exercise. -significant increases in oxygen delivered to the tissue, carbon dioxide returned to the lungs, and minute ventilation provides for appropriate levels of alveolargas concentrations during aerobic exercise.

hyperoxic breathing

-breathing oxygen enriched gas mixtures during rest periods of following exercise may positively affect exercise performance. -the procedure remain controversial

altitude

-changes begin to occur at elevations greater than 3,900 feet increased pulmonary ventilation, increased cardiac output at rest and during submaximal exercise due to increase in heart rate -values begin to return to normal within 2 weeks -several chronic physiological and medical adjustments occur during prolonged altitude exposure

oxygen uptake

-increases during an acute bout of aerobic exercise -is directly related to mass of exercising muscle, metabolic efficiency, nad exercise intensity

cardiovascular adaptations

-increases in maximal cardiac ouput, stroke volume, and fiber capillary density -increased parasympathetic tone leads to decreases in resting and submaximal exercise heart rates

age and sex

-maximal aerobic power decreases with age in adults -aerobic power values of women range from 73% to 85% of values of men -general physiological respone to training is simialr in men and women

blood transport of gases and metabolic by products

-most oxygen in blood is carried by hemoglobin -most carbon dioxide removal is from its combination with water and delivery to the lungs in the form of bicarbonate. -during low to moderate intensity exercise, enough oxygen is available that lactic acid does not accumulate because the removal rate is greater than or equal to production rate. -aerobic exercise level at which lactic acid begins to show an increase in termed the onset of b lood lactate accumulation or OBLA

muscular adaptations

-one of the fundamental adaptive responses to aerobic endurance trianing is an increase in the aerobic capacity of the trained musdculature. -this adaptation allows the athlete to perform a given absolute intensity of exercise with greater ease after aerobic endurance training

aerobdic endurance training results in

-reduced body fat -increase maximal oxygen uptake -increase running economy -increase respiratory capacity -lower blood lactate concentration at submaximal exercise -increase mitochondrial and capillary densities -improve enzyme activity

respiratory adaptations

-ventilatory adaptations are highly specific to activities that involve the type of exercise used in training -training adaptations include increased tidal volume and brewathing frequency with maximal exercise.

smoking

acute effects of tobacco smoking could impair exercise performance

proper exercise variation, intensity, and maintenance programs and active recovery periods can

adequately protect against serious detraining effects

cardiac output

amount of blood pumped by the heart in liters per minute. SV * HR

one of the most commonly measured adaptations to aerobic endurance training is

an increase in maximal oxygen uptake associated with an increase in maximal cardiac output

cardiovascular responses

greater volumes of training affect heart rate

maximal oxygen uptake

greatest amount of oxygen can be used at the cellular level for entire body

detraining

if inactivity, rather than proper recovery, follows exercise, an athlete loses training adaptations

the intensity of training i one of the most important factors

in improving and maintaining aerobic power.

bone and connective tissue adaptations

in mature adults, the extent to which tendons, ligaments, and cartilage grow and become stronger is proportional to the intenisty of the exercise stimulus, especially from weight bearing activities

during 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 concentration of these gases.

endocrine responses

overtraining may result in a decreased testosterone to cortisol ratio, decreased secretion of growth hormone, and changes in catecholamine levels

tapering

planned reduction of volume in training that occurs before an athletic competition or a planned recovery microcycle

stroke volume

quantity of blood ejected with each beat

genetic potential

upper limit of an individual's genetic potential dictates absolute magnitude of training adaptation

markers of aerobic training

-decrease performance -decreased percentage of body fat -decreased maxiaml oxygen uptake -altered blood pressure -increased muscle soreness -decresed muslce glycogen -altered resting heart rate -increased submaximal exercise heart rte -decrease lactate -increase creatine kinase -altered cortisol concentration -decrease total testosterone concentration -decrease ratio of total testosterone to cortisol -decrease ratio of free testosterone to cortisol -decrase ratio of total testosterone to sex hormone binding globulin -decrease sympathetic tone (decreased nocturnal and resting catecholamines) -increased sympathetic stress response -change in mood states -decrease performance in psychomotor speed tests

control of local circulation

-during aerobic exercise, blood flow to active muscles is considerably increased by dilation of local arterioles -at the same time, blood flow to other organ systems is reduced by constriction of the arterioles

gas responses

-during high intensity aerobic exercise, the pressure gradients of oxygen and carbon dioxide cause the movement of gases across cell membranes. -diffusing capcities of oxygen and carbon dioxide increase dramatically with exercise, which facilitates their exchange.

cardiovascular responses (cardiac output)

-from rest to steady state aerobic exercie, cardiac output initially increases rapidly, then more gradually, and subsequently reaches a plateau -with maximal exercise, cardiac output may increase to four times for the resting level

CV responses

-heart rate increases linearly with increase in intensity -oxygen uptake

biochemical responses

-high training volume results in incrased levels of creatine kinase, indicating muscle damage -muscle glycogen decreases with prolonged periods of overtraining

acute aerobic exercise results in

-increase cardiac output -increase stroke volume -increase heart rate -increase oxygen uptake -increase SBP -increase blood flow to active muscles -decrease DBP

blood doping

can improve aerobic exercise performance and may enhnace tolerance to ceertain environmental conditions. It is unethical and poses serious health risks

overtraining syndrome can lead to

dramatic performance decreases in all athletes; the most common cause is intensified training without adequate recovery

neural adaptations

efficiency is increased and fatigue of the contractile mechanisms is delayed

resting oxygen uptake

estimated at 3.5 ml/kg/min this value is defined as 1 metabolic equivalent