This chapter discusses adenosine triphosphate (ATP), which is the donor of the free energy that is used for muscle contraction, for the supporting ionic pumps that regulate muscle electrical activity, and for biosynthesis. It also talks about the molecule of ATP that is made up of a molecule of adenosine and consists of a purine base, a five-carbon sugar, and a chain of three phosphate groups. It also analyszes the phosphate groups that are attached by what are known as high-energy bonds, which means that considerable energy is required to produce the attaching reaction. The chapter points out that the formation of the high-energy bond is known as phosphorylation, while the breaking of the bond is known as hydrolysis. It details how adenosine diphosphate (ADP) is formed when a molecule of ATP is hydrolyzed and loses one of its phosphate groups.
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Chapter
Biochemical Bases for Performance
Chapter
Cardiorespiratory Bases for Performance
This chapter provides a background on cardiovascular and respiratory systems from the perspective of the athlete. Their most important function is to deliver oxygen to the exercising muscles and to remove carbon dioxide, while maintaining blood flow to vital organs. The chapter explains how the cardiovascular system matches the blood flow to skeletal muscle to its metabolic rate. It also analyszes two circuits of the cardiovascular system that are arranged both in parallel and in series: pulmonary circuit and systemic circuit. The chapter explains that the pulmonary circuit conducts blood from the right side of the heart to the lungs and back to the left side of the heart. It clarifies how the systemic circuit conducts blood from the left side of the heart to all the tissues in the body and back to the right side of the heart.
Chapter
Cardiovascular physiology
This chapter focuses on the cardiovascular system. This provides cells with oxygen and nutrients and transports metabolic waste products away from cells. The chapter talks about the heart and the extensive system of vessels known as the circulatory system. It explains that the heart acts as a pump while the circulatory system acts as a transport system for blood. The chapter highlights the normal functioning of the cardiovascular system which is essential in order to maintain an appropriate cellular environment for all cells in the human body. It emphasizes that the heart can be thought of as a pump that ejects blood into the pulmonary and systemic circulations.
Chapter
The endocrine system
This chapter reviews how the endocrine system, together with the nervous system, controls the multitude of physiological processes in the body and ensures that homeostasis is achieved. It discusses the formation of hormones from derivatives of amino acids, peptides and proteins, and lipids. It also analyszes the chemical nature of the process by which anan individual hormone determinesing where its receptor is located. The chapter clarifies how the overall plasma levels are maintained at the appropriate level proportion by negative feedback mechanisms, although hormone secretion may display circadian rhythms. It mentions the pituitary gland. This is described as the master endocrine gland by virtue of the number of physiological processes it controls.
Chapter
Gastrointestinal physiology
This chapter highlights reproduction, which is the process of producing offspring from parents wherein the genetic material from each of the parents is transmitted to the offspring. It refers to genetic fusion that occurs when a male sperm cell fertilizes a female ovum or egg cell. It also details how the fertilized egg undergoes a series of phenomenal changes over the nine months following fertilization. This results in the birth of an offspring. The chapter describes the male gamete formation as a continuous process, while a female gamete production is a cyclical process and only occurs for about 30 to 35 years in females. It covers fertilization, which completes the meiotic division of ova and results in the formation of a zygote, ultimately dividing and growing to produce a fetus.
Chapter
Gastrointestinal physiology
This chapter deals with the digestive system, which is considered as one of the most important systems in the human body. The digestive system is described to be a hollow tract that runs from the mouth to the anus with other associated organs. The chapter outlines the functions of the digestive system, which is the digestion and absorption of nutrients and the defence, transport, and elimination of waste products. It also explains how ingested nutrients are broken down into their constituent parts by physical and chemical processes. The chapter refers to the stomach as the organ which acts as a reservoir allowing digestion to occur so that effective absorption can take place. It discusses the absorption of nutrients and water that takes place in the intestine, with the vast majority occurring in the small intestine.
Chapter
Integrative physiology
This chapter demonstrates the integrative nature of physiological systems and the effect that certain applied examples have on these systems. It reviews examples on the effects of acute and chronic aerobic exercise on the cardiovascular system, the effect of nutrition on health, and the effect of ambient temperature and pressure on physiological systems. It also talks about how acute aerobic exercise can cause an increase in cardiac output due to increases in stroke volume and heart rate and can lead to increases in mean arterial pressure due to increases in cardiac output. The chapter cites the prevalence of obesity. This has significantly increased in recent times, with numerous health consequences that are associated with this disorder. It analyszes the regulation of appetite that involves psychological and physiological interactions.
Chapter
Introduction
This chapter considers underlying molecular and cellular elements and the link between structure and function in physiology to provide an understanding of the structures within the body. It discusses the body in terms of the hierarchical nature of organization from the molecular level through to the organismal level. It also highlights the elemental composition of the vast majority of the body which is formed from carbon, oxygen, hydrogen, oxygenydrogen, carbon, and nitrogen. The chapter analyzes an individual's body weight in terms of body composition, which is accounted for by water and is found in a variety of compartments. Given that water accounts for most of an individual’s body weight, the chapter looks in depth at the forms this water takes. It explains that the water within the body has a variety of solutes dissolved in it that. These form extracellular fluid and intracellular fluid, each of which has a unique composition.
Chapter
Introduction to Training for High Performance
This chapter discusses the quality of an athlete's performance as the result of a complex blend of many factors that determines the athlete's potential to excel, is his or herwith a major factor being genetic endowment. It mentions body size, cardiovascular traits, proportions of muscle-fiber types, and gross motor coordination as factors that are genetically predetermined. It also emphasizes the most important factor affecting athletic performance, which is the amount and suitability of the training that precedes the competition. The chapter defines training as the stimulation of biological adaptations that result in an improvement in performance in a given task. It focuses on determining the most effective stimulus to exploit the body's ability to adapt to potentially harmful stimuli in order to effect biological changes that will improve performance.
Chapter
Muscle
This chapter provides an overview of the distinct anatomical and contractile properties of the three types of muscle in the human body: skeletal, smooth, and cardiac muscles. It highlights the interaction of actin and myosin filaments. This is central to the contraction of all types of muscle. The chapter points out that skeletal and cardiac muscle are termed ‘striated muscle’ because of the existence of sarcomeres. It also discusses the regulation of contraction of in all three muscle types, which depends on the movement of calcium into the cytosol of the cell. The chapter clarifies that in skeletal muscle, increases in cytosolic calcium are due to central nervous system activation, while in smooth muscle, increases in cytosolic calcium can be due to central nervous system activation. It explains the increases in cytosolic calcium in the cardiac muscle. These are due to the action of the conduction system of the heart.
Chapter
Muscle Physiology
This chapter focuses on muscle physiology. It considers how muscles are controlled by the nervous system and how the nervous system and muscles work together to produce what are commonly called strength and power performance. It also demonstrates the ability of muscles to generate force and power and the ability of the nervous system to activate the muscles appropriately for a given task in which performance depended. The chapter describes the composition of muscles of cells called muscle-fibers, which range in thickness from about 50-100 μm and in length from a few to several millimeteres. It refers to myofibrils that make up about 85% of the contents of a muscle-fiber, while the remaining 15% are largely composed of sarcoplasmic reticulum (SR), mitochondria, glycogen granules, and fat droplets.
Chapter
The nervous system
This chapter talks about the fundamental role of the nervous system, which is control and coordination. It describes neurons as the functional elements of the nervous system. Neurons are supported by a second group of cells called glial cells, whose role purpose is to support neurons and ensure that they function effectively. It also reviews neural control. This is characterized by its electrical mediation, its rapidity, and its duration of response. The chapter discusses neurons as being characterized by a large resting membrane potential, the polarity of which is reversed during an action potential. It demonstrates how neurons communicate with each other by the release of chemical compounds called neurotransmitters.
Chapter
Neuromuscular Bases for Performance
This chapter explains how the nervous system controls muscle contraction as reflected in the activation of motor units. It focuses on exercise-induced fatigue and its effects on neural and muscle function and considers factors such as muscle size and muscle temperature that affect strength, power, and speed performance. It also mentions the motor unit, which is the common pathway for muscle control wherein several parts of the brain and spinal reflexes control the force of muscle contraction. The chapter talks about motoneurons, which consists of a neuronal cell body situated in the ventral horn of the spinal cord or within nuclei of the brain stem. It refers to dendrites that extend from the soma and a motor axon that extends from the soma, which is part of a motor nerve serving a muscle.
Chapter
Other Considerations
This chapter looks at blood glucose, which is the primary energy source for cells in the brain and the central nervous system and the only energy source for red blood cells. It details how an hour of heavy continuous exercise training, competing in a team sport, or a 30-second sprint-training intervals can reduce muscle glycogen concentration by more than 60%. It also examines carbohydrates that are converted by digestive enzymes to the six-carbon sugar, glucose, before they enter the glycolytic pathway or be stored as glycogen. The chapter talks about nutritionists that have derived a numerical scale known as the glycemic index (GI), a numerical scale developed by nutritionists which rates various foods by how quickly and to what extent they increase blood glucose. It refers to international competitions wherein athletes must travel by air across a number of time zones to participate.
Chapter
Peaking, Tapering, and Overtraining
This chapter focuses on training given on a set of physiological adaptations, wherein training stimulus is reduced once maximal adaptation has occurred and a different form of training is introduced. It explains how peaking occurs when an athlete completes a training program incorporating the correct sequencing of different forms of training. It also defines overtraining as the condition that arises when the magnitude of the training stimulus chronically exceeds the athlete's capacity to adapt to it. The chapter talks about the suppressive effect of overtraining on certain components of the immune system. This makes the athlete less resistant to infection and common illnesses, such as upper-respiratory-tract infections (URTI). It explains how the recognition of the early indications that an athlete may be approaching the overtrained state is a major challenge for a coach.
Book
Duncan MacDougall and Digby Sale
The Physiology of Training for High Performance consists of three parts. Part I, which is about the physiological bases for athletic training, starts off with an introduction to training for high performance. It moves on to look at the biochemical bases and cardiorespiratory bases for performance. It looks at muscle physiology and then finishes with the neuromuscular bases for performance. Part II covers training for different sports and activities. It looks at endurance sports, anaerobic events, team sports, as well asnd training for power, strength, and speed as well. The last part, which presents additional factors affecting performance, looks at peaking, tapering, and overtraining; stretching and flexibility, and, finally, some other considerations, including nutrition, testing, altitude, and para-athletics.
Chapter
Renal physiology
This chapter reviews the vital role of the renal system in the human body, which is the production and elimination of urine. It describes nephron as the functional unit of the kidney that is responsible for the formation of urine and talks about blood plasma that is filtered within the nephrons and substances that are secreted and reabsorbed in the process of urine formation. It also examines the extent of water and sodium loss via urine. This is controlled by the actions of arginine vasopressin, aldosterone, and atrial natriuretic peptide. The chapter highlights the major role that the renal system plays in the regulation of the acid–base balance. It discusses the increase in blood pH that leads to an increase in the quantity of bicarbonate secreted in urine in order to return blood pH to normal.
Chapter
The respiratory system
This chapter details the principal role of the respiratory system, which is to provide an exchange of gases between the body and the environment. It outlines the functions of the respiratory system, such as its contribution to the maintenance of plasma pH and the production of sound. It also explains how the respiratory system ensures that adequate amounts of oxygen are delivered to tissues and carbon dioxide is efficiently removed when exchanging gases in a variety of environmental challenges. The chapter talks about the paired lungs that sit inside the thorax, which are formed from a series of bifurcations of a single trachea. It details how air enters the lung by a suction pump, wherein inspiration results in an increase in volume and a decrease in pressure inside the lungs.
Chapter
Stretching and Flexibility
This chapter discusses muscle stretching exercises performed by most athletes, which make up part of their warm-up before training sessions and competition. It analyszes regular stretch training that athletes do to increase their flexibility, which can be defined as the maximum range of movement achievable without injury at a joint or series of joints. It also talks about a high level of flexibility that is important in many types of performance. The chapter reviews issues of whether pre-activity stretching prevents injury or enhances or hinders performance and highlights be methods of flexibility training. It considers the different types of stretching and their effect on the muscle-tendon unit.
Book
Ian Kay and Gethin Evans
Thrive in Human Physiology provides an initial introduction to human physiology. It then looks at control and co-ordination in terms of the nervous system and the endocrine system. It moves on to musculoskeletal physiology and movement, cardiovascular physiology, respiratory physiology, renal physiology, gastrointestinal physiology, reproductive physiology, and integrative physiology.
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