Basics of Exercise Physiology

Definitions to considerWhat is Physical Activity?Body movement produced by muscle action that increases energy expenditure. eg: activities of daily living such as shopping, gardening, housekeeping, child rearing, work-related activities, etc

What is Exercise?Planned, structured, repetitive, and purposeful physical activitye.g.: training for or performing athletics, sports, or recreationalactivities such as jogging, roller-blading, ice skating, swimming, etc.

FitnessGeneral Fitness State of health and well being.

Specific FitnessA task-oriented definition based on the ability to perform specific aspects of sports or occupation.

Components of FitnessHealth RelatedBody Composition Cardiovascular EnduranceFlexibilityMuscular EnduranceStrength

Skill RelatedAgilityCoordinationSpeed Reaction TimeBalancePower

Exercise Physiology?Definition: the study of how the body (cell, tissue, organ, system) responds in function and structure to (1) acute exercise stress, and (2) chronic physical activity.Sports PhysiologyApplies the concepts of exercise physiology to training the athlete and enhancing the athletes sport performance.

Fuel for Energy

Fuel for Energy

CarbohydratePrimary source of energyAll carbohydrate is ultimately broken down to glucose or stored in the muscle or liver as glycogen Dietary sources of starches and sugar to replenish carbohydrate reserve.

FATLarge source of energy during prolonged, less intense exercise. Rate of energy release is slow. Less readily available for cellular metabolism because it must be reduced from its complex form.

Protein Minor energy source Utilized during severe depletion of the other macronutrients or during starvation. It can be used to generate free fatty acids FFAs for cellular energyOr converted to glucose through the process of gluconeogenesis. It can supply 5 to 10% of the energy needed to sustain prolonged exercise.

Fuel for Energy

Anaerobic vs Aerobic Metabolism

Fuel for EnergyAnaerobic Creation of energy through the combustion of carbohydrate in the absence of oxygen.

Aerobic The creation of energy through the combustion of carbohydrates and fats in the presence of oxygen.

Fuel for EnergyThree Energy Systems Immediate (ATP Phosphocreatine System)Short Term (Glycolytic System) Long Term (Oxidative System) ATP- Adenosine triphosphate

Immediate System Simplest of the energy systems.This process does not require oxygen, but it can occur in the presence of oxygen.During the first few seconds of intense muscular activity (sprinting), adenosine triphosphate (ATP) is maintained at a relatively constant level as phosphocreatine (PCr) declines.Combination of ATP and PCr stores can sustain the muscles energy needs for up to approximately 15 sec of an all out sprint.

Short term system Liberation of energy through the breakdown of glucose. Anaerobic glycolysis entails a complex process involving 10 12 enzymatic reactions for the breakdown of glycogen to lactic acid.Does not produce large amount of ATP.Predominates during early minutes of high intense exercise (all out sprint for 1 2 min).

Long Term System Most complex of the three system Slow to turn on, but has a tremendous energy yielding capacityPrimary method of energy production during endurance events.

Interaction of the three energy systems Do not work independent of each other. Each system contributes to the total energy needs of the body. One system usually predominates, depending on the activity.

Percentage of Emphasis on the Three Metabolic Energy Systems in Training For Various Running Events

Running Event ImmediateShort TermLong Term 100 m 9532200 m9523400 m80155800 m306551,500 m2055253,000 m2040405,000 m10207010,000 m51580Marathon (42.2 km)5590

Exercise training

The repeated use of exercise to improve physical fitness.Permits adaptations within the physiological systems to minimize the disturbance to homeostasis resulting from exercise

This means exercise intensity can be increased for a given distance or duration, or a given intensity can be sustained longer

What is Exercise Training?

Adaptations to ExerciseAcute adaptationsThe changes in human physiology that occur duringexercise or physical activity.

Chronic AdaptationsThe alterations in the structure and functions of the bodythat occur in response to the regular completion ofphysical activity and exercise.

Types of Training

Resistance Training Aerobic Training Anaerobic Training

Resistance Training Is a form of strength training in which each effort is performed against a specific opposing force generated by resistance.

Resistance TrainingTypes of Resistance TrainingIsometric Training Facilitate recovery and reduce muscle atrophy and strength lossFree WeightsMore motor recruitment Gain control of the free wgtStabilize the wgtMaintain body balance

Eccentric Training Maximize gains in strength and sizeVariable Resistance Training Resistance reduced at weakest points and increased at strongest points. Isokinetic Training Contract at maximal force at all points in the range of motionPlyometricsBridge the gap between speed and strength trainingElectrical Stimulation TrainingReduce loss of strength and muscle size

Adaptations to resistance trainingNeural Control of strength gains Muscle Hypertrophy (Transient vs. Chronic)Muscle SorenessAcute Muscle SorenessEdemaDelayed Onset of Muscle Soreness and InjuryStructural Damage Inflammatory Reaction

Aerobic Training (Cardiorespiratory Endurance Training)

Adaptations to Aerobic exerciseImprovements in endurance that accompany regular aerobic training results from multiple adaptations to the training stimulus.Cardiovascular AdaptationsHeart RateStroke Volume Heart SizeCardiac Output Blood Flow Blood Pressure Blood Volume

Adaptations to Aerobic exerciseRespiratory Adaptations: Pulmonary Ventilation Pulmonary Diffusion A V Oxygen Difference

Muscular AdaptationsMuscle Fiber Type Capillary SupplyMyoglobin ContentMitochondrial Function

Adaptations to Aerobic exerciseMetabolic Adaptations Lactate ThresholdRespiratory Exchange RatioOxygen Consumption

Factors affecting response to aerobic trainingLevel of conditioning and VO2 max Hereditary SexHigh Responders and Low Responders

Anaerobic Training

Adaptations to anaerobic exerciseAnaerobic power and capacityMuscular adaptationsGlycolytic Enzymes

Exercise Prescription

Exercise PrescriptionMedical ClearanceMedical EvaluationGraded Exercise Testing

Exercise Prescription Mode/Type of ExerciseFrequency Duration Intensity

Exercise ProgramMEWarm Up (stretching activities)Anaerobic / Endurance/ Resistance/ Flexibility Training Cool Down (stretching activities)

Fitness is a product. Most would agree its a product of exercise and/or physical activity and can be broken into components**Who can tell me what happens physiologically to our bodies when we start running?Breathe faster known as increased pulmonary ventilationHeart beats faster known as increased heart rateBody burns energy known as beta oxidation or glycolysisSweat known as sweat

Then there are some chronic or longer term reactions to training. What are some of these?Lower heart rateIncreased stroke volumeDecreased ventilationIncreased metabolismIncreased hypertrophy of muscle tissue******