Principles of Aerobic Exercise PDF

Principles of Aerobic Exercise C. Kisner, L. Colby, and J. Borstad. 2018“Therapeutic Exercise: Foundations and Techniques” 7th edition, F. A. Davis Company Ch7: Principles of Aerobic Exercise  Fitness  “Fitness is a general term used to...

Principles of Aerobic Exercise C. Kisner, L. Colby, and J. Borstad. 2018“Therapeutic Exercise: Foundations and Techniques” 7th edition, F. A. Davis Company Ch7: Principles of Aerobic Exercise  Fitness  “Fitness is a general term used to describe the ability to perform physical work.”  Performing physical work requires  Cardiorespiratory functioning  Muscular strength and endurance  Musculoskeletal flexibility  To become physically fit, individuals must engage in frequent large- muscle use and cardio-respiratory system-strengthening physical activity  Maximum Oxygen Consumption (VO2max)  It is a measure of the body’s capacity to use oxygen  It is the maximum amount of oxygen consumed per minute when the individual has reached maximum effort  It is usually measured when performing an exercise that uses many large muscle groups  Endurance  Endurance (a measure of fitness) is the ability to work for prolonged periods of time and the ability to resist fatigue  It includes:  Muscular endurance: the ability of an isolated muscle group to perform repeated contractions over a period of time  Cardiovascular endurance: the ability to perform large muscle dynamic exercise, such as walking, swimming, and/or biking for long periods of time  Aerobic Exercise Training (Conditioning)  Aerobic exercise training is augmentation of the energy utilization of the muscle by means of an exercise program  The improvement of the muscle’s ability to use energy is a direct result of:  Increased levels of oxidative enzymes in the muscles  Increased mitochondrial density and size  Increased muscle fiber capillary supply  Adaptation  The cardiovascular system and the muscles used adapt to the training stimulus over time  Significant changes can be measured in as little as 10 to 12 weeks  Adaptation results in increased efficiency of the cardiovascular system and the active muscles  Performance improves in that the same amount of work can be performed after training but at a lower physiological cost  Deconditioning “Deconditioning occurs with prolonged bed rest”  Energy Systems  Energy systems are metabolic systems involving a series of biochemical reactions resulting in the formation of  Adenosine triphosphate (ATP)  Carbon dioxide  Water  The cell uses the energy produced from the conversion of ATP to adenosine diphosphate (ADP) and phosphate (P) to perform metabolic activities  Energy Systems  There are three major energy systems  ATP-PC (Phosphagen) System  Anaerobic Glycolytic System  Aerobic System  ATP-PC System (Phosphagen)  Anaerobic metabolism  It is used for ATP production during high intensity exercise and short duration (100 meters sprinting)  Phosphocreatine breaks down and releases energy, which is used to form ATP.  This energy system is the most rabidly available source of ATP, it provides energy for the muscle to work for approximately 15 seconds  It doesn’t depend on chemical reactions and oxygen transportation  Anaerobic Glycolytic System  Anaerobic metabolism  It is the major supply of ATP during high intensity exercise and short duration (400 meters sprinting)  Glycogen breaks down into glucose and then into pyruvic acid, this process forms the ATP  This system is slower than ATP-PC System by 50%, it provides energy for the muscle to work for approximately 30-40 seconds  It doesn’t depend on oxygen transportation and it uses only carbohydrate  Aerobic System  This energy system is used during low intensity exercise and long duration  It depends on Oxygen as the production of ATP is the resultant of food oxidation  It also requires complex chemical reactions  Muscle fibers Slow-twitch fibers (type I) Fast-twitch fibers (type IIB) Fast-twitch fibers (type IIA) “Slow contractile response” “Fast contractile response” “Characteristics of both type I and type IIB fibers and are recruited for both anaerobic and aerobic activities.” “Have rich in myoglobin and “Have a low myoglobin content mitochondria” and few mitochondria” “Have a high oxidative capacity “Have a high glycolytic and a low anaerobic capacity” capacity” “They are recruited for “They are recruited for activities demanding activities requiring power” endurance”  Physiological Response to Aerobic Exercise  Cardiovascular Response to Exercise  Increased Cardiac Output  Net Reduction in Total Peripheral Resistance  Respiratory Response to Exercise  Gas exchange (O2, CO2) increases across the alveolar-capillary membrane  Minute ventilation increases  Determinants of an Exercise Program  Effective endurance training for any population must produce a conditioning or cardiovascular response  Elicitation of the cardiovascular response depends on:  Intensity of exercise  Duration of exercise  Frequency of exercise  Determinants of an Exercise Program  Intensity of exercise  Overload Principle  A conditioning response occurs generally at 60% to 90% maximum heart rate (50% to 85% VO2 max)  High intensity exercise for a shorter period of time leads to greater improvement in VO2 max than moderate intensity exercise for a longer period of time  Determinants of an Exercise Program Duration The optimal duration of exercise for cardiovascular conditioning depends on the total work performed, exercise intensity and frequency, and fitness level  The greater the intensity of the exercise, the shorter the duration needed for adaptation  The lower the intensity of exercise, the longer the duration needed  A 20- to 30-minute session is generally optimal at 60% to 70% maximum heart rate  When the intensity is below the heart rate threshold, a 45-minute continuous exercise period may provide the appropriate overload  For high-intensity exercise, 10- to 15-minute exercise periods are adequate  Determinants of an Exercise Program Frequency Optimal frequency of training is generally three to four times a week  A frequency of two times a week does not generally evoke cardiovascular changes Mode  Any exercise involves large muscle groups like running and cycling  Exercise Program Components  There are three components of the exercise program:  A warm-up period  The aerobic exercise period  A cool-down period  General Guidelines for an Aerobic Training Program  Establish the target heart rate and maximum heart rate  Warm up gradually for 5 to 10 minutes:  Include stretching and repetitive motions at slow speeds, gradually increasing the effort  Increase the pace of the activity so the target heart rate can be maintained for 20 to 30 minutes:  Include fast walking, running, bicycling, swimming and cross-country skiing  Cool down for 5 to 10 minutes with slow, total body repetitive motions and stretching activities  The aerobic activity should be undertaken three to five times per week  General Guidelines for an Aerobic Training Program  To avoid injuries from stress:  Use appropriate equipment: correct footwear  Avoid running, jogging, or aerobic dancing on hard surfaces such as asphalt and concrete  To avoid overuse syndromes in structures of the musculoskeletal system:  Use a proper warm-up and stretching of muscles  Progression of activities should be within the tolerance of the individual  Individualize the program of exercise