Ch.6 Adaptations to aerobic endurance training
Refers to the volume of gas a person inhales per minute. It is a significant factor in exercise and sport performance. It is primarily responsible for increasing or decreasing the rate of ventilation based on the amount of carbon dioxide in the blood when exercising. In order to clear excess carbon dioxide from the blood, respiration must increase and once levels have been normalized or exercise has ceased, the rate of ventilation will decrease.
minute ventilation
Overtraining syndrome can lead to dramatic performance decreases in all athletes. The most common cause is intensified training without adequate __________
recovery
What does acute aerobic exercise increase?
-CO (cardiac output) -HR (heart rate) -Systolic BP -SV (stroke volume) -Oxygen uptake -Blood flow to active muscles
How is oxygen carried in blood?
-Dissolved in the blood plasma (small amounts because oxygen is not readily soluble in fluids) -Hemoglobin (Primarily)
Aerobic endurance training results in several changes in cardiovascular function (relating to the heart and blood vessels), what are they?
-Increased maximal cardiac output -Increased SV (volume of blood pumped from the left ventricle per beat) -Reduced HR at rest and submaximal exercise -Increased muscle fiber capillary density (supports delivery of oxygen, nutrients, hormones, and removal of heat, carbon dioxide, and metabolic by products in the muscle)
What are some strategies for preventing OTS (over training syndrome)?
-adequate nutrition -sufficient sleep and recovery -variety in intensity and volume in training programs -keep record of athletes performance for indicators -Players should have access to a multidisciplinary health team (coach, physician, nutritionist, psychologist) to discuss any issues related to their lives
What bone and connective tissue adaptations does aerobic exercise provide?
-improvements in bone mass (running and high intensity aerobics). The activity must be significantly more intense than the daily activities that person normally engages in, so as to exceed the minimum threshold intensity of the bone. This intensity must systematically increase in order to continually overload the bone. In mature adults, the extent to which tendons, ligaments, and cartilage grow and become stronger is proportional to the intensity of the exercise stimulus, especially from weight bearing activities. As with bone and muscle, exercise intensity that consistently exceeds the strain placed on the connective tissues during daily activities is needed to create connective tissue (tendons, ligaments, cartilage) changes.
What are external and individual factors that may influence adaptations of endurance training?
1. Altitude -Increased formation of hemoglobin and red blood cells -Increased diffusing capacity of oxygen through the pulmonary membranes -Maintenance of the acid-base body fluids by renal (kidney) excretion of HCO3- and through hyperventilation -Increased capillarization (the formation and development of a network of capillaries to a part of the body) **Reduced performance, compared to sea level, is generally expected with altitude exposure regardless of the period of acclimatization. 2. Hyperoxic breathing -Breathing oxygen-enriched gas mixtures during exercises or rest period. It may increase the amount of oxygen carried by the blood and therefore increase the supply of oxygen to working muscles. 3. Smoking -Increased airway resistance due to nicotine-related bronchiole constriction or increased fluid secretion and swelling in the bronchial tree due to the irritation of smoke. -Paralysis of the cilia on the surfaces of the respiratory tract by nicotine, which limits the ability to remove excess fluids and foreign particles, causing debris to accumulate in the respiratory passageways and adding to the difficulty of breathing. 4. Blood doping -The practice of artificially increasing red blood cell mass (increases the blood's ability to carry oxygen and thus increasing oxygen availability to working muscle) as a means to improve athletic performance. -serious health risks to athletes and is unethical. Individuals can have infusion of their red blood cells or red blood cells from someone else through administration of erythropoietin (EPO), which stimulates red blood cell production. Infusion of red blood cells increases red blood cell mass, but for a few weeks. Infusion of the drug EPO produces changes over weeks and lasts as long as it is taken. -Improves aerobic performance and may enhance tolerance of certain environmental conditions. 5.Genetic potential -The upper limit of an individuals genetic potential contributes significantly to the absolute magnitude of the training adaptations 6. Age and sex -Physiological adaptations to aerobic endurance training vary according to age and sex. Maximal aerobic power decreases with age in adults as a consequence of various physiological changes that accompany aging (reduced muscle mass and strength (sarcopenia) along with increased fat mass) -Men produce more aerobic power than women but both sexes have similar physiological responses to training. Differences could be because of mens larger heart, hemoglobin content, and women's higher body fat
what is the average resting bp reading?
120 mmHg (systole) / 80 mmHg (diastole)
Explain altitude training
Altitude training causes several adaptations both acutely and chronically. Acute adaptations are necessary to stabilize respiration and heart rate, while chronic adaptations primarily impact cellular function. The acute adaptations are an increase in pulmonary ventilation and cardiac output in both resting and exercise states. The chronic adaptations are oriented towards delivering sufficient oxygen into the working tissues, which requires increased myoglobin concentrations (5-15%), greater diffusion capacity through the pulmonary membranes, increased capillary density in trained muscle, and increased buffering capacity of lactate through hyperventilation and greater availability of bicarbonate. The drawbacks to altitude training center around length of time chronic adaptations persist, as generally these adaptations normalize over a month.
This is the differentiation between the amount of oxygen being transported through the arterial and venous divisions of the circulatory system. This is the primary means of evaluating the amount of oxygen being unloaded into active tissue during exercise, and is crucial in determining aerobic fitness as the difference is an element component in the Fick equation.
Arteriovenous oxygen difference
What neural (relating to a nerve or the nervous system) adaptations does aerobic exercise provide?
Athletes produce more efficient locomotion during activity with lower energy expenditure. -This is due to a rotation in neural activity among synergist muscles and among motor units within a muscle. Rather than maintaining a constant state of activation, synergistic muscles alternate between active and inactive to maintain low-level muscular force production)
Is a reduction in the resting heart rate due to chronic aerobic exercise . It is a physiological adaptation to aerobic exercise and is directly related to the hypertrophy of the left ventricle that increases the stroke volume capacity of the heart. At rest, this increased stroke volume will result in a lower resting heart rate (BPM) because the excess stroke volume reduces the need to beat as frequently as would be considered normal (80-100 BPM). In untrained or elderly populations _______ may be indications of decreased electrical activity in the sinoatrial node and someone experiencing symptoms not related to exercising should be directed to a physician to get checked
Bradycardia
After carbon dioxide is formed in the cell, how is it removed?
Carbon dioxide easily diffuses across the cell membrane and is transported to the lungs. Only a small percent of carbon dioxide (5%) is produced during metabolism (is carried in plasma). Carbon dioxide combines with water and delivered to the the form of bicarbonate (HCO3-)
What is the primary functions of the cardiovascular system during aerobic exercise?
Deliver oxygen and other nutrients to working muscles and remove metabolites (intermediate products of metabolic reactions ,usually small molecules) and waste products.
The partial or complete loss of training-induced adaptations in response to an insufficient training stimulus. Governed by the principle of training reversibility, which states that whereas physical training results in severe physiological adaptation that enhance athletic performance, stopping or markedly reducing training induces a partial or complete reversal of these adaptations, compromising athletic performance.
Detraining
What does acute aerobic exercise decrease?
Diastolic blood pressure
What is the impact of exercise on diffusion rates?
Diffusion refers to the movement of gases from areas of high concentration to areas of lower concentration. The movement of the gases along the gradient is due to the partial pressure exerted by each molecule of gas. During exercise, the partial pressures of the gases are altered depending on their location in the circulatory system. The changes in pressures will determine whether or not the gases move into or out of the circulation during exercise.
_____1____ is the volume of blood available to be pumped by the left ventricle after diastole. this is very significant in regards to stroke volume because this volume of blood is what will be pumped from the heart to the rest of the body and working muscles. Over time, the working fibers of the heart become stretched, which allows for greater ____1_____, and increases the volume of blood ejected during systole .
End-diastolic volume
This is the equation for assessing maximal oxygen uptake Vo2 = Q x a - VO2 difference a=arterial oxygen content q=cardiac output vo2= venous oxygen content the difference in volume between the arterial content and the venous content is whats being unloaded to the working muscles. You must also know how hard the heart is working (Q)
Fick equation
This mechanism is related to the concept that the force of contraction is a function of the length of the fibers of the muscle wall.
Frank-Starling mechanism
What endocrine (the glands that secrete hormones) adaptations does aerobic exercise provide?
Increases in hormonal circulation and changes at the receptor level (both number of receptors and turnover rate) -Net protein breakdown from the muscle from stress induced cortisol secretion.
What muscular adaptations does aerobic exercise provide?
Increases the aerobic capacity of the trained musculature, allowing the athlete to perform a given absolute intensity of exercise with greater ease. More impressively, after training an athlete can exercise at a greater relative intensity of a now higher maximal aerobic power. At a cellular level, this increase is due to increases in MITOCHONDRIA (organelles in cells that are responsible for producing ATP via oxidation of glycogen and free fatty acids) and MYOGLOBIN (a protein that transports oxygen within the cell).
This is Metabolic equivalent of tasks and is used to assess energy expenditure of various physical activities. The central limiting factor of this assessment is the general assumptions tat are made regarding a specific individual, as this measure cannot account for individual differences which include fat mass, fat-free mass, intensity, and overall conditioning of the person.
METS
It is the GREATEST amount of oxygen that can be used by an athlete. This amount is usually indicated when O2 consumption plateaus. It is the best measure of cardiovascular fitness because it indicates the upper limit capacities of the endurance athlete across varying heart rates and work loads. In anaerobic athletes this is indicative (a sign) of the anaerobic lactate threshold and aerobic potential.
Maximal oxygen uptake
This is referred to as the average blood pressure throughout the cardiac cycle. It is not the average of systolic and diastolic pressures, because the arterial pressure usually remains nearer the diastolic level than the systolic level during a greater portion of the cardiac cycle. Thus, the ________ is usually less than the average of the systolic and diastolic pressures.
Mean arterial pressure (MAP)
What are the muscular adaptations to aerobic training?
Muscular adaptations to aerobic training center on enhancing the muscular capacity for sustained work, which include hypertrophy of type I fibers, increased mitochondria, and increased myoglobin activity. The hypertrophy of type I fibers is caused by the increased recruitment during aerobic activities, and the cross-sectional increase is not as great as that of type II fibers. The increased mitochondrial density in the muscle leads to greater ATP production, and is significant in enhancing aerobic capacity (ATP is produced in the mitochondria). The other significant adaptation in muscle is the increased activity of myoglobin, which is the protein responsible for transporting oxygen and iron into the muscle cell. The greater concentration of myoglobin increases the amount of oxygen available for energy production within the working muscles.
overreaching vs overtraining
Overreaching is an abbreviated period of time that is characterized by excessive training , and can be resolved with rest and recovery. The primary differences between overreaching and overtraining are the duration of the time period that the training state persists, as overtraining is a chronic state and overreaching phases can be a structured part of an athletes competitive preparation. Overreaching can function to force an athlete to go beyond his or her ability to adapt and recover, which produces an over stressing on all physiological systems, and with planned rest and recovery allowing the body to supercompensate. Planned overreaching phases can be significantly beneficial to an athlete, while overtraining is detrimental.
Explain the blood transport of gases and metabolic byproducts during exercise
Oxygen is carried through circulation via hemoglobin at a level of approximately 3ml per liter of plasma. Carbon dioxide is transported out of the cell via diffusion and into the plasma for transport to the lungs for clearance. This process is a bit more involved as buffering CO2 relies on bicarbonate and water, which requires canalization by carbonic anhydrase, in order to buffer the hydrogen ions accumulating in the blood. This process is supported through the natural acid-base buffering capacity of the hemoglobin in order to maintain blood PH balance. Once exercise intensity reaches a level where aerobic metabolism is not sufficient to maintain PH balance,then lactic acid begins to accumulate quickly, and is referred to as onset of blood lactate, or OBLA.
What is the cardiac output equation?
Q= SV X HR Q=Cardiac output SV=stroke volume (mL/min) HR= heart rate (BPM)
This is a reference point for workload of the heart during exercise. It is the number of beats per minute multiplied by the systolic pressure that the heart is working against. This provides direct insight into how hard the heart is working via the hemodynamic response. When performing high-intensity workloads, being able to quantify performance is essential for evaluating athlete effort during training sessions, but also provides a means of assessing cardiovascular responses and progression over time.
Rate pressure product
Explain cardiovascular adaptations to aerobic exercise
Responses to aerobic exercise are related to unloading oxygen into working muscles as effectively as possible. Adaptations to aerobic exercise include increased cardiac output, reduced HR at rest and during submaximal exercise, increased SV, and a significant increase in density in the microvasculature. These adaptations occur over time with the most significant changes occurring with the hypertrophy of the left ventricle and the increased contractile strength of that chamber.
What types of training can improve and maintain aerobic power?
Short, high intensity bouts of interval sprints with a short rest period can improve maximal oxygen uptake while maintaining and even improving aerobic power.
The planned reduction of volume of training (usually in duration and frequency but not intensity) that occurs before an athletic competition or planned recovery microcycle. This type of reduction in training is designed to enhance athletic performance and adaptations.
Tapering
Explain Over training
The term overtraining refers to the combination of physiological and psychological status of an athlete that persists for weeks or months. This state is caused by training too often, excessive training in volume and intensity, poor nutrition/ reduced calorie intake, or inadequate rest provisions in the programming. This training state generally presents with symptoms such as extreme fatigue, frequent illness, and minor injuries that do not seem to resolve over time. Overtraining syndrome can lead to decreased performance, sleeplessness, and possibly injury. Overtraining syndrome is a chronic state and requires varying degrees of intervention. There is much discussion regarding possible interventions to resolve this issue. The most common recommendations range from reduction in training intensity and volume to taking substantial time off from training (up to 6 months or longer) in order to recover. There are two types of overtraining syndrome, parasympathetic and sympathetic. Parasympathetic overtraining is marked by an increase in parasympathetic activity at rest, which would be highlighted by a reduction in heart rate at specific workloads. The sympathetic form, most commonly seen in athletes performing power sports, is highlighted by an increase in heart rate at rest and generally inability to relax and achieve a rested state. In both cases the most often recommendations are reduction in training volume or cessation of training-related activities for a significant period of time, or until symptoms have been resolved. Note: Sympathetic nervous system =fight or flight responses Parasympathetic nervous system=Rest, digest and homeostasis
The amount of air inhaled and exhaled with each breath
Tidal volume
Is the measure of the vascular resistance in the systematic circulation. ____________ in the systematic circulation is caused by the opening and closing of vessels throughout the systematic circulation. These circulation-controlling mechanisms are referred to as vasoconstriction, which constricts blood flow, and vasodilation, which increases blood flow. ________ and pulmonary vascular resistance differentiate from one another via the aspect of the vascular system that is responsible for generating the resistive forces that must be overcome in order to move blood through the system. This resistance is concerned with the resistance from the vasculature of the lungs. _________= (mean arterial pressure-mean vascular pressure) / Q (cardiac output)
Total peripheral resistance
This is the primary means of reducing blood flow in specific tissues both at rest and during exercise. During exercise, specific organ systems and certain functions are limited because of increased blood flow to other organs and tissues. The reason for constricting blood flow to certain tissues during exercise is to maximize the available blood volume for the active tissue sites that need oxygen, but also to reduce the functions of certain systems during exercise (i.e. digestion)
Vasoconstriction
Is the process of blood vessels and arteries dilating to allow for maximum blood flow into an organ or tissue. This response is invaluable (extremely useful) in response to aerobic and anaerobic exercise. In both forms of exercise, this response transports oxygenated blood, nutrients, and electrolytes to working tissues. It also plays a significant role in allowing for the maximum transport of CO2 for clearance in the lungs, or for transporting lactate and other assorted waste materials from working tissues for buffering.
Vasodilation
This is referred to the amount of blood that is returning to the heart. This increases as an adaptation to aerobic conditioning.
Venous return
This is a method of indexing an athletes ability to utilize oxygen. This delineates (outlines) the rate of oxygen being inhaled in comparison to the amount of oxygen that is being exhaled (VE/VO2). This equivalency provides the coach with insight into how effectively the athlete unloads the oxygen being brought into the body and into the working muscle tissue. This measurement will indicate whether an athlete is in condition for the competitive season, as this will decrease in an athlete that effectively unloads oxygen into the active tissues.
Ventilation equivalent
Is the ratio of minute ventilation and oxygen uptake during exercise, which is Ve/VO2 for oxygen consumption and Ve/VCO2 when evaluating carbon dioxide output. At the onset of lactate accumulating in the blood more rapidly than can be effectively buffered, ventilation rate increases at a rate disproportionate to the rate of oxygen uptake in tissues. The lactate threshold and the _________ are very closely connected because of the necessity of clearing excess lactate and CO2 from the body.
Ventilatory equivalent
the functional unit of the pulmonary system where gas exchange occurs.
alveoli
areas of the respiratory passage (trachea, nose, mouth, bronchi, and bronchioles) where it is not functional for gas exchange.
anatomical dead space
The volume of blood pumped through the heart specifically by a right or left ventricle in the time period of one minute. The volume of blood being pumped is a factor of the hearts stroke (mL/min) and the heart rate (BPM)
cardiac output
Estimates the pressure exerted against the arterial walls when NO blood is forcefully ejected through the vessels. It provides an indication of peripheral resistance and can decrease with aerobic exercise due to vasodilation.
diastolic blood pressure (diastole) lowest number in bp reading
is the movement of oxygen and carbon dioxide across a cell membrane. It results from the movement of gas from high concentrations to low concentrations
diffusion
Aerobic endurance training is generally associated with alterations in body composition , assuming appropriate nutritional uptake. Aerobic endurance training has little to no effect on __________. Long term programs can have greater decreases in body fat, excessive training may lead to catabolic activity.
fat-free mass
refers to the amount of oxygen consumed by the body's tissues. The oxygen demand of working muscles increases during an acute bout of aerobic exercise and is directly related to the mass of exercising muscle, metabolic efficiency, and exercise intensity. Exercises requiring a larger muscle or greater level of work, is likely to be associated with a higher total oxygen uptake. Increased metabolic efficiency allows for an increase in oxygen uptake, especially at maximal exercise.
oxygen uptake
refers to alveoli that do not receive necessary blood flow, experience poor ventilation, or have other restrictive issues along the alveolar surface that reduces functional gas exchange capacity. It is most commonly seen in diseased populations that include various chronic obstructive pulmonary diseases such as emphysema.
physiological dead space
Estimates the pressure exerted against the arterial walls as blood is forcefully ejected during ventricular contraction. Combined with oxygen, it can be used to describe the myocardial oxygen consumption (work) of the heart.
systolic blood pressure (systole) highest number in bp reading
Aerobic endurance training results in: -Reduced body fat -Increased maximal oxygen uptake -Increased running economy -Increased respiratory capacity -Lower blood lactate concentrations at sub-maximal exercise -Increased mitochondrial and capillary densities -Improved enzyme activity T/F?
true
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 (where gas exchange occurs) and minute ventilation increases to maintain appropriate alveolar concentrations of these gases. T/F
true
Proper exercise variation, intensity, maintenance programs, and active recovery periods can adequately protect against serious detraining effects. T/F
true
What respiratory (a series of organs responsible for taking in oxygen and expelling carbon dioxide) adaptations does aerobic exercise provide?
ventilation is unaffected or moderately affected by aerobic exercise. If training adaptations occur it is usually: -Increased tidal volume (the amount of air breathed in and out in one cycle)
