Unit One: Concepts of Physical Fitness PDF

UNIT ONE 1. CONCEPTS OF PHYSICAL FITNESS 1  1.1 Meanings and Definitions of Terms 1.1.1 Physical fitness Is an ability to meet the ordinary, as well as unusual demands of daily life safely and effectively...

UNIT ONE 1. CONCEPTS OF PHYSICAL FITNESS 1  1.1 Meanings and Definitions of Terms 1.1.1 Physical fitness Is an ability to meet the ordinary, as well as unusual demands of daily life safely and effectively without being overly fatigued. it is the body’s ability to function effectively and efficiently, and contributes the total quality of life It has two dimensions  health related physical fitness and skill related physical fitness Is not a static factor and it varies from individual to individual. 2  1.1.2 Physical Activity Is bodily movement produced by skeletal muscles that results in energy expenditure Is categorized in to aerobic and anaerobic physical activity. Aerobic physical activity: activity that is performed long enough to maintain or improve an individual’s cardiorespiratory fitness. E.g walking, basketball, soccer, or dancing Anaerobic physical activity: high-intensity activity that exceeds the capacity of the cardiovascular system to provide oxygen to muscle cells. E.g Sprinting and power lifting 3  1.1.3 Physical Exercise/Exercise is physical activity that is planned, structured, repetitive, and purposive in the sense to maintain one or more components of physical fitness. Physical activity and exercise has the following common elements 1) Are movement produced by skeletal muscles that expends energy 2) Are measured by kilocalories ranging continuously from low to high 3) Are positively correlated with physical fitness So exercise is not synonymous with physical activity: it is a subcategory of physical activity. 4  1.1.4 Sport Is an organized, competitive form of play. We cannot think of sport without thinking of competition Without the competition, sport becomes simply play or recreation Play can at times be sport, but strictly speaking, sport is never simply play 5  1.2 General Principles of Fitness Training 1.2.1 Principle of Overload A greater than normal stress or load on the body is required for training adaptation to take place. However the old saying, “No pain, No gain.” is not acceptable E.g, a beginning weightlifter performs squats with 10 repetitions at 150 pounds. After 2 weeks the lifter feels easier during the lift The lifter adds 20 pounds and continues with the newly established stress of 170. The lifter will continue to get stronger until his/her maximum capacity has been reached, at which point the lifter’s strength will simply plateau. 6  1.2.2 FITT Principle In exercise, the amount of stress placed on the body can be controlled by four variables: Frequency: how often Intensity: how hard/degree of difficulty Time (duration) : how long Type : type of exercise Each variable can be used independently or in combination with other variables to impose new stress and stimulate adaptation. 7  1.2.3 Principle of Rest, Recovery, and Periodization Rest and recovery(recuperation) must take place in proportionate amounts to avoid too much stress One systematic approach to rest and recovery is the principle of periodization Periodization: method of organizing workouts into blocks or periods which is consisted of work and rest periods. In periodization training is organized on a daily, weekly, monthly, and even multi-annual cycles, called micro-, meso-, and macrocycles, respectively. Training without periodization, leads to overtraining syndrome. condition of chronic stress from physical activity affecting the physical and psychological states of an individual or athlete 8  Overtraining syndrome has the following symptoms  weight loss  loss of motivation  inability to concentrate or focus  feelings of depression  lack of enjoyment in activities normally considered enjoyable  sleep disturbances  change in appetite 9  1.2.4 Principle of Reversibility Adaptations to training can be lost over time if training is stopped This principle is best described by “Use it or lose it.” E.g in CRE key areas like VO2max, SV, and Q all declined with detraining while submaximal heat rate increased. Muscular strength, muscular endurance, and flexibility all show similar results after a period of detraining. Detraining: no training at all / decreasing the amount of training 10  1.2.5 Principle of Individual Differences It states that everyone responds to training differently The factors for this difference are: Genes Age Gender training status at the start of a program Rapid improvement is experienced by those with a background that includes less training Those who are well trained improve at a slower rate. 11  UNIT TWO 2. THE HEALTH BENEFITS OF PHYSICAL ACTIVITY 2.1. Physical Activity and Hypokinetic Diseases/ Conditions Hypokinetic diseases: are conditions related to inactivity or low levels of habitual activity. Physical inactivity is a public health problem in the 21st century. Each year at least 1.9 million people die as a result of physical inactivity. Individuals who do not exercise regularly are at a greater risk for developing chronic diseases (CHD, hypertension, hypercholesterolemia, cancer, obesity, and musculoskeletal disorders) Chronic diseases are defined broadly as conditions that last 1 year or more and require ongoing medical attention or limit activities of daily living or both. 12 13  Thus ACSM recommended that every adult should perform 30 min of moderate-intensity physical activity on most, preferably all, days of the week.  Daily physical activity is the base for physical fitness 14 Try to be active for at least 30 min every day  2.2. Physical Activity and Cardiovascular Diseases According to WHO (2011) CVD caused 17.3 million deaths (30%) worldwide in 2008, and it is projected to cause more than 26 million deaths by 2030. More than 80% of those cardiovascular deaths occurred in low- and middle-income countries. 15  2.2.1 Coronary Heart Disease (CHD) Is caused by a lack of blood supply to the heart muscle (myocardial ischemia) resulting from a progressive, degenerative disorder known as atherosclerosis. Risk factors for CHD Age Family History Hypercholesterolemia Hypertension Tobacco use Diabetes Mellitus Overweight and Obesity, and Physical Inactivity. High HDL-cholesterol in the blood decreases CHD risk. Exercise reduce the risk of CHD by a factor of 1.5 to 2.4 16 2.2.2 Hypertension/high blood pressure Is a chronic, persistent elevation of blood pressure that is clinically defined ≥140/90mmHg It is the leading cardiovascular risk factor, attributing 13% of deaths worldwide WHO (2011). It is the primary risk factor for all types of stroke. About 15% to 40% of the global adult population has hypertension. 17  Exercise Prescription for Individuals with Hypertension (ACSM, 2013) Mode: endurance activities supplemented by resistance exercises Intensity: Moderate-intensity endurance (40–60%) and resistance training (60–80% 1-RM) Duration:30–60 min or more of continuous or accumulated aerobic physical activity per day, and a minimum of one set (8– 12 reps) of resistance training exercises for each major muscle group. Frequency: Most, preferably all, days of the week for aerobic exercise; 2 or 3 days/wk for resistance raining. 18  2.2.3 Hyper-cholesterolemia and Dyslipidemia Hypercholesterolemia: is an elevation of total cholesterol (TC) in the blood Is also referred to as hyperlipidemia ( increase in blood lipid levels) Dyslipidemia refers to an abnormal blood lipid profile. Risk factors for hypercholesterolemia Age Gender family history Alcohol smoking 19  Cholesterol: is a waxy, fatlike substance found in all animal products (meats, dairy products, and eggs). The body can make cholesterol in the liver and absorb it from the diet. Cholesterol is used to build cell membranes, to produce sex hormones, and to form bile acids necessary for fat digestion Lipoproteins: are part of the complex transport system that exchanges lipids among the liver, intestine, and peripheral tissues. 20  The four main classes of lipoproteins are 1. Chylomicron: derived from the intestinal absorption of triglycerides (TG) 2. VLDL: made in the liver for the transport of triglycerides 3. LDL: a product of VLDL metabolism that serves as the primary transporter of cholesterol; and 4. HDL: involved in the reverse transport of cholesterol to the liver. Individuals with low HDL-C or high TC levels (dyslipidemia) have a greater risk of heart attack. Those with lower HDL-C (45 min a carbohydrate drink should be ingested. Consume 60 g of carbohydrate per hour of exercise. Insoluble carbohydrate is not recommended for high intensity events Avoid eating fats during exercise as they are difficult to digest. Fiber and protein content, and high carbohydrate concentration and osmolality should be avoided as it may cause gastrointestinal problems. During long, low intensity competitions solid food can be eaten in the early stages of the event. 51  Drinking during exercise Large volumes of drink stimulate gastric emptying more than small volumes. Ingest a fluid volume of 6-8 ml/kg BW, 3-5 min prior to the start to ‘prime’ the stomach, followed by smaller amounts (2-3 ml/kg BW) every ~15-20 min. After drinking a large quantity, the stomach may feel empty and uncomfortable. So eat some easily digested solid food. 52  3.2.3 Nutrition after Exercise When to eat after exercise? The quicker you consume food or drink after a workout, the quicker your body will recover. The enzymes that are responsible for making glycogen are most active immediately after your workout. The longer you wait, the longer it will take to start the recovery process. have a carbohydrate-rich drink or snack as soon as possible - ideally within 30 minutes and no later than 2 hours. 53  When and how much to drink after exercise ? Start drinking before you even get showered and changed Drink 750 ml of water for every 0.5 kg of BW lost during exercise. Drink around 500 ml over the first 30 minutes, little and often What to drink after exercise? For exercise less than an hour Plain water is good followed by a carbohydrate-rich snack within 2 hours. For longer & intense workouts A drink containing carbohydrate and sodium speed your recovery. Try fruit juice diluted with an equal volume of water 54  UNIT FOUR 4. Health Related Components of Fitness and Principles of Exercise Prescription 4.1 Health Related Components of Fitness overall goal of a total health related physical fitness program is to optimize the quality of life. Specific goals are To reduce the risk of disease To improve total physical fitness Five components of health-related physical fitness are: 1. cardiorespiratory endurance, 2. muscular strength, 3. muscular endurance, 4. flexibility and 5. body composition 55 1. Cardiorespiratory Fitness heart’s ability to pump oxygen-rich blood to the working muscles efficiently blood vessels ability to transport blood to the working muscles muscle’s ability to use that oxygen & produce energy without being fatigue 2. Muscular Strength Ability of a muscle to generate force during a single maximal contraction It is important in almost all activities of our daily living Weight training results in an increase in the size and strength of muscles. 3. Muscular Endurance 56   4.2 Muscle Structure and Contraction Muscle Structure:  Muscle is a collec­tion of long thin cells called fibers and surrounded by a dense layer of connective tis­sue called fascia  Muscles are attached to bone by connective tissues known as tendons.  Muscular contraction causes tendons to pull bones which result movement. Muscle Contraction:  Muscle contraction is reg­ulated by signals coming from motor nerves.  Motor nerves originate in spinal cord and send nerve fibers to individual muscles.  The motor nerve and all of the muscle fibers it controls is called a motor unit. 57  Contraction begins when a nerve impulse reaches the neuromuscular junction. The nerve impulse triggers the con­traction by permitting the interaction of the two contractile proteins (actin and myosin). The movement of the myosin filament over the actin filament is called "slid­ing" and results in muscular shortening and the generation of force. That’s why theory of muscle contraction is called sliding filament theory. when a motor nerve stop sending signals to a muscle, contrac­tion stops. Sometimes uncon­trolled muscular contraction occurs which result muscle cramp. 58  4.3Types of Muscle Contractions Isotonic (dynamic) contractions: Result in movement of a body part with same load. E.g. lifting a dumbbell Are three types concentric, eccentric, and isokinetic contractions. 1. Concentric contractions  are contractions that result in muscle shortening.  E.g. upward movement of the arm 2. Eccentric contractions (negative contractions) are contractions in which the muscle exerts force while it lengthens.  E.g. resisting the a weight during the lowering phase of weight lifting. 3. Isokinetic Contractions are concentric or eccentric contractions performed at a constant speed.  A weight-lifting machine that controls the rate of muscle shortening and lengthening 59  Isometric (static) contraction: Results muscular tension but no movement of body parts. o E.g. exerting force against the wall. Occur in the postural muscles of the body during sitting or standing o Holding the head upright 60  3.5 Muscle Fiber Types Types of skeletal muscle fibers 1. Slow twitch 2. fast twitch All differ in their speeds of 3. Intermediate contraction and fatigue resistance Most human mus­cles contain a mixture of all three fibers types. 1. Slow-Twitch Fibers: contract slowly and produce small amounts of force are highly resistant to fatigue. are red in appearance produce large quantities of ATP aerobically  suited for a low-intensity prolonged exer­cise like walking or slow jogging. most postural mus­cles are composed primarily of slow-twitch fibers. 61 2. Fast-Twitch Fibers: contract rapidly and generate great amounts of force fatigue quickly. are white and have a low aerobic capacity, produce ATP anaerobically. used during rapid activities (jumping, sprinting, and weight lifting. 3.Intermediate Fibers: possess a characteristics of fast- and slow-twitch fibers. contract rapidly, produce great force, contract more quickly and produce more force than slow-twitch fibers but contract more slowly and produce less force than fast- twitch fibers. are more fatigue resistant than fast-twitch fibers but less fatigue resistant than slow-twitch fibers. 62 4. Flexibility  is the ability to move joints freely through their full range of motion.  flexibility is useful in preventing muscle-tendon injuries and reducing low back pain.  Stretching exercises are best to increase flexibility Types of Stretching exercise for flexibility 1. ballistic 2. sta­tic 3. proprioceptive neuromuscular facilita­tion(PNF) 63  Static Stretching  is a method of slowly lengthening a muscle to a point at which further movement is limited and holding it (usually 10-20 seconds repeated 3-4 times). Benefit risk of injury is minimal compared to ballistic stretching may reduce muscle stiffness when performed during cool down Proprioceptive Neuromuscular Facilitation Is new technique of improving flexi­bility It combines stretching with alternating con­tracting and relaxing of muscles. Types 1. contract-relax (C-R) stretching and 2. contract-relax/antagonist contract (CRAC) stretching. 64 1. contract-relax (C-R) stretching: first contracting the muscle to be stretched. Then, after relaxing the muscle, the muscle is slowly stretched. 2. contract-relax/antagonist contract (CRAC) stretching. Uses the same contract-relax routine but adds to this the contraction of the antagonist muscle. 65. The end 66