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.
Physiological Adaptations to Aerobic Endurance Training - ENZYME ACTIVITY
Creatine Phosphokinase. Myokinase. Phosphofructokinase. Lactate dehydrogenase. Sodium-potassium ATPase.
Creatine Phosphokinase: Increases. Myokinase: Increases. Phosphofructokinase: Variable. Lactate dehydrogenase: Variable. Sodium-potassium ATPase: May slightly increase.
Physiological Adaptations to Aerobic Endurance Training - METABOLIC ENERGY STORES
ATP.
Creatine Phosphate.
Glycogen.
Triglycerides.
ATP: Increases.
Creatine Phosphate: Increases.
Glycogen: Increases.
Triglycerides: Increase.
Physiological Adaptations to Aerobic Endurance Training - CONNECTIVE TISSUE
Ligament.
Tendon Strength.
Collagen Content.
Bone Density.
Ligament: Increases.
Tendon Strength: Increases.
Collagen Content: Variable.
Bone Density: Not change or Increases.
Physiological Adaptations to Aerobic Endurance Training - BODY COMPOSITION
% BF.
Fat-free Mass.
% BF: Decreases.
Fat-free Mass: No change.
Chronic Cardiovascular Adaptations
Aerobic endurance training requires proper progression, variation, specificity, and overload if physiological adaptations are to take place.
Chronic 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 breathing frequency with maximal exercise.
Chronic Neural Adaptations
Efficiency is increased and fatigue of the contractile mechanisms is delayed.
May result in a rotation of neural activity among synergists (i.e. rather than maintaining a constant state oof activation, synergistic muscles alternate between active and inactive to maintain low-level muscular force production) and motor units within a muscle; allows for more efficient locomotion during the activity with lower energy expenditure.
Chronic Muscular Adaptations
One of the fundamental adaptive responses to aerobic endurance training is an increase in the aerobic capacity of the training musculature.
This adaptation allows the athlete to perform a given absolute intensity of exercise with greater ease after aerobic endurance training.
Chronic Bone and Connective Tissue Adaptations
In mature adults, the extent to which tendons, ligaments, and cartilage grow and become stronger is proportional too the intensity of the exercise stimulus, especially from weight-bearing activities.
Stimulating new bone formation means that aerobic exercise must be significantly more intense than the person’s normal daily activities.
Chronic Endocrine Adaptations
Aerobic exercise leads to increases in hormonal circulation and changes at the receptor level.
High-intensity aerobic training increasing the absolute secretion rates of the many hormones in response to maximal exercise.
Trained athletes have blunted responses to sub maximal exercise.
Often associated with an increase in protein breakdown from the muscle.
General Adaptations of Aerobic Endurance Training
One of the most commonly measured adaptations t aerobic endurance training is an increase in maximal O2 uptake associated with an increase in maximal cardiac output.
Intensity of training is one oof the most important factors in improving and maintaining aerobic power.
Aerobic endurance training results in reduced BF, increased O2 uptake, increased respiratory capacity, lower blood lactate concentrations, increased mitochondrial and capillary densities, and improved enzyme activity.
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training
Altitude. Hyperoxic Breathing. Smoking. Blood Doping. Genetic Potential. Age and Sex.
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training - ALTITUDE
Changes begin to occur at elevations greater than 3,900 ft. (1,200m).
Increased pulmonary ventilation (breathing).
Increased HR.
Values return toward normal within 2 weeks.
Chronic physiological and metabolic adjustments during prolonged altitude exposure
Pulmonary Ventilaiton.
Acid-base.
Cardiovascular.
Hematologic.
Hyperventilation (increased pulmonary ventilation) during rest and exercise b/c of increased breathing frequency.
Acid-base: Body fluid becomes more alkaline.
Cardio: increased cardiac output and sub maximal HR, SV remains the same or is slightly lowered.
Hematologic: increased RBC production, hematocrit, and viscosity, and decreased plasma volume.
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training - HYPEROXIC BREATHING
Breathing O2-enriched gas mixtures during rest periods or following exercise may positively affect exercise performance, although the procedure remains controversial.
I.e. breathing air from an O2 tank.
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training - SMOKING
Acute effects of tobacco could impair exercise performance.
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training - BLOOD DOPING
Artificially increasing RBC mass is unethical and poses serious health risks, yet it can improve aerobic exercise performance and may enhance tolerance to certain environmental conditions.
Blood doping can be accomplished thorough infusion of an individual’s own RBC or those from someone else, or through erythropoietin (EPO), which stimulates RBC production.
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training - GENETIC POTENTIAL
The upper limit of an individual’s genetic potential dictates the absolute magnitude of the training adaption.
External and Individual Factors Influencing Adaptations to Aerobic Endurance Training - Age and Sex
Maximal aerobic power decreases with age in adults.
Aerobic power values of women range from 73% to 85% of the values of men.
The general physiological response to training is similar in men and women.
Cardiovascular Responses too Aerobic Overtraining Syndrome (OTS)
Greater volume of training affect HR.
Resting HR can be increased or decreased.
HRV can decrease as a result of OTS (reduced parasympathetic input or excessive sympathetic stimulation).
Exercise-induced maximum HR decreases.
Biochemical Responses too Aerobic Overtraining Syndrome (OTS)
High training volume results in increased levels of creatine kinase, indicating muscle damage.
Lactate concertations either decrease or stay the same when training volume increases.
Blood lipids and lipoproteins not changed.
Muscle glycogen decreases with prolonged periods of overtraining (may contribute to lower lactate responses).
Endocrine Responses too Aerobic Overtraining Syndrome (OTS)
Overtraining may result in decreased testosterone-to-cortisol ratio (5%-50%; possible marker is 30%+), decreased secretion of GH, and changes in catecholamine levels.
Strategies for Preventing OTS
Good nutrition, sleep, and recovery time.
Coaches should track athlete’s training program, and the program should provide a variety in intensity and volume.
Keeping records of performance in order to catch potential markers.
Most importantly, athletes should have access to a multidisciplinary health team (coach, doctor, nutritionist, and psychologist).
Markers of Aerobic Overtraining
Performance. BF%. Maximal O2 Uptake. BP. Muscle Soreness. Muscle Glycogen. Resting HR. HRV. Submit. Exercise HR. Lactate. Creatine Kinase. Cortisol Concentration. Total Testosterone Concen. Ratio of Total Test.-to-Cortisol. Ratio of Free Test.-to-Cortisol. Ratio of Total Test.-Sex hormone binding globulin. Sympathetic Tone. Sympathetic Stress Response. Mood States. Performance in Psychomotor Speed Tests.
Performance: Decrease. BF%: Decreased. Maximal O2 Uptake Decreased. BP: Altered. Muscle Soreness: Increased. Muscle Glycogen: Decreased. Resting HR: Altered HRV: Decreased. Submaxal. Exercise HR: Increased. Lactate: Decreased. Creatine Kinase: Increased. Cortisol Concentration: Altered. Total Testosterone Concen: Decreased. Ratio of Total Test.-to-Cortisol: Decreased. Ratio of Free Test.-to-Cortisol: Decreased. Ratio of Total Test.-Sex hormone binding globulin: Decreased. Sympathetic Tone: Decreased (decreased nocturnal and resting catecholamines). Sympathetic Stress Response: Increased. Mood States: Altered. Performance in Psychomotor Speed Tests: Decreased.
Detraining
If inactivity, rather than proper recovery, follows exercise, an athlete loses training adaptations.
Tapering is the planned reduction of volume of training (usually in duration and frequency but not intensity) that occurs before an athletic competition or a planned recovery microcycle.
Proper exercise variation, intensity, maintenance programs, and active recovery periods can adequately protect against serious detraining effects.
Detraining definition
Partial or complete loss of training-indicted adaptations in response to an insufficient training stimulus.
Governed by the principle of train reversibility.
Aerobic endurance adaptations are most sensitive too periods of inactivity because oof enzymatic basis (exact cellular mechanisms are unknown).
