NUTR 1000 – 003Exam #4 Study Guide Lectures: 19 - 12Lecture 19 (September 7)Chapter 11: Nutrition and FitnessWhat is Physical Fitness and Why is it Important?- Physical Fitness: good health or good physical condition is primarily the result of exerciseand proper nutritiono 5 Basic Components of Physical Fitness Cardiorespiratory Endurance- Ability to sustain cardiorespiratory exercise for an extended periodof time (ex. Running, biking)- Cardiovascular & respiratory systems must provide enough oxygenand energy to muscles Muscle strengthening - Ability to produce force for brief time (ex. Weight lifters, body builders, cheerleaders, ballet dancers) Muscle endurance- Ability to exert force for brief time; ability to sustain the lift for a long period Flexibility- Range of motion around a joint (improved with stretching)o Reduces risk of injuryo Gymnast vs. Toe Touching- Stretchingo Static—relax then extend the muscleo Dynamic—stretching muscles while movingo Ballistic—bouncing—greater chance of injury Body Composition- Proportion of muscle, fat, water, and other body tissues that makeup body weight (can change w/o changing body weight)- Redistribution of weight- More muscle vs. fat; muscles are more compact than fatHealth Benefits of Physical Activity- Nearly half of American lead a sedentary life; physical activity is essential for long, healthy life- Physical Activity includes: o Day-to-day activitieso Exercise- Physical activity and consuming a healthy diet benefit everyone- Improves health and fitnesso Assists in weight management; improved body composition- Reduced risk of cardiovascular disease and of developing certain cancerso Improves overall cardiac function (strengthens heart muscle)o Improves blood lipid regulation – increases HDL and helps decrease LDL- Reduces risk of type 2 diabetes risk- Improves bone health- Enhancement of moodPhysical Fitness Programs- Based on 5 components of fitness - Get the most out of Physical Fitness programs by using the FITT principleo Frequency, Intensity, Type, & Timeo American College of Sports Medicine Frequency of physical activity- 60 minutes/week of moderate-intensity activity fr some health benefits- 60 to 90 minutes daily to lose weight effectively- 150 min/week of moderate-intensity aerobic activity for substantial health benefits Intensity of physical activity- Rate of perceived exertion (RPE) measures intensity of cardiorespiratory exercise- Target heart rate shows exercise intensity through heart rate (% of maximum)- Repetition maximum (RM) refers to intensity of strength training; 1 RM is the max weight that can be lifted one time Type of physical activity- Several types of exercise Time (duration) of physical activity Injuries can occur if one exercises too frequently or with too much intensity - The Progressive Overload Principle can help improve fitness over timeo The body adapts to physical activities, producing fitness plateauo Modify one or more FITT principles to increase exercise and improve fitnessLecture 20How are Carbohydrate, Fat, and Protein Uses during Exercise- Physically Fit = regular physical activity + right foods and fluids- Energy production is accomplished 2 ways: o Anaerobic (does not require oxygen) ATP (adenosine triphosphate) CP (creatine phosphate)o Aerobic (requires oxygenEnergy MetabolismFor anaerobic production of energy the body relies heavily on two high energy molecules in the muscle cellsATP (adenosine triphosphate) is the major energy containing compound• ATP is composed of a molecule of adenosine attached to a tail of 3 phosphate atoms.• When one of these phosphates is removed, energy is released as a byproduct, resulting in ADP (adenosine diphosphate) • ATP is stored in limited supply in the cell• Breakdown can support only a few seconds of intense exercise.2nd high energy molecule in the muscle cell isCreatine phosphate • a compound containing creatine attached to a single phosphate.• Energy is produced when the phosphate is split off from the creatine• The free phosphate atom joins with ADP to form ATP This process regenerates ATPCreatine phosphate is produced in the body (liver and kidneys)Creatine phosphate is also obtained from foods (esp. meat and fish)• A small amount of creatine is stored in the muscles • Depleted after about 10 seconds of high intensity activityWhat Fuels Our Activities?Continued exercising brings a shift from anaerobic to aerobic • brings on heavy breathing and an increased oxygen intake• ATP cannot be generated fast enough• Body shifts from the anaerobic energy pathway to the aerobic pathway • At this point, the body begins to burn cho (glucose) and fat (fatty acids) and some protein to produce ATPThe type and amount of energy that is used depends on: --intensity and duration of exercise--your nutritional status--your level of physical fitness.Cho and fat contribute most while protein is best used for muscle growth and recovery.- Muscle glycogeno Carbohydrate is the primary energy source during any exerciseo Storage: 650 gms x 4 calories/gram = 2600 kcalsMost CHO is stored in the muscles for ready use• Average adult male glycogen stores:525 gms muscles x 4 = 2100 kcals 100 gms liver x 4 = 40025 gms blood x 4 = 100------------------------= 2600 kcalsEnough energy for about 2 hrs of moderate exercise• Well-trained muscles store 20 to 50 percent more glycogen than untrained musclesLiver glycogen is converted to glucose and dumped into the bloodstream• maintains normal blood glucose during activity and rest• Blood glucose is the energy source for the brainCarbohydrates are used for energy no matter how intense the exerciseThe amount of carb used is affected by • Intensity, level of fitness, initial muscle glycogen stores and carb supplementation during exerciseLactic acid is produced when glucose is broken down at a very high rate and there is not enough oxygen available• Produced and removed from body continuously• Can be used for energy during low-intensity exerciseAs exercise intensity increases, more lactate is produced and accumulates in the muscles faster than it can be used for energy or shuttled away• Can cause increased pH (acidity) in the muscle cells• Causes fatigue• Can improve lactate shuttle by increased trainingDuration affects the amount of glucose and glycogen you use.Glucose and glycogen use increases with increased duration Glycogen stores become