Chapter 13 Nutrition and Physical Activity
Copyright 2010, John Wiley & Sons, Inc. Exercise, Health and Fitness Fitness is defined as the ability to perform routine physical activity without undue fatigue. The overload principle assumes that the body will adapt to the stresses placed on it. Aerobic exercise includes endurance exercises such as jogging, swimming or cycling, or any exercise that increases heart rate and requires oxygen in metabolism. The cardiorespiratory system includes the circulatory and respiratory systems, delivering oxygen and nutrients to the cells.
Copyright 2010, John Wiley & Sons, Inc. Exercise, the Heart and the Muscles Regular aerobic exercise strengthens the heart muscle, increases stroke volume and decreases the resting heart rate. The resting heart rate can be measured by counting the number of pulses per minute while at rest. Aerobic capacity is the body’s maximum ability to generate ATP by aerobic metabolism during exercise. Aerobic capacity is also called VO 2 max. Stress or overload during exercise causes muscles to adapt by increasing in size and strength. This is called hypertrophy. When muscles are not used, they atrophy, becoming smaller and weaker. Exercise builds and maintains muscles. People who are fit have a greater proportion of lean body tissue than those who are not fit.
Copyright 2010, John Wiley & Sons, Inc. Health Benefits of Exercise In addition to increased flexibility and the ability to easily perform daily activities, benefits of regular exercise include: Weight management Cardiovascular health Diabetes prevention or management Bone and joint health Possible reduction of cancer risk Psychological health
Copyright 2010, John Wiley & Sons, Inc. Exercise Recommendations
Copyright 2010, John Wiley & Sons, Inc. Target Heart Rates During Aerobic Exercise
Copyright 2010, John Wiley & Sons, Inc. Components of a Good Exercise Regimen
Copyright 2010, John Wiley & Sons, Inc. Suggestions for Starting and Maintaining an Exercise Program
Copyright 2010, John Wiley & Sons, Inc. Fueling Exercise Aerobic metabolism is metabolism in the presence of oxygen. Glucose, fatty acids and amino acids are completely broken down to form CO 2 and H 2 0 and to produce ATP. Anaerobic metabolism is metabolism in the absence of oxygen. Each molecule of glucose produces two molecules of ATP. Glucose is metabolized in this way when oxygen cannot be supplied quickly enough to the tissues to support aerobic metabolism. Anaerobic metabolism is also called anaerobic glycolysis.
Copyright 2010, John Wiley & Sons, Inc. Fueling Exercise by the Minute
Copyright 2010, John Wiley & Sons, Inc. The Process of Anaerobic Metabolism
Copyright 2010, John Wiley & Sons, Inc. The Effect of Exercise Intensity
Copyright 2010, John Wiley & Sons, Inc. Nutrient Needs for Physical Activity
Copyright 2010, John Wiley & Sons, Inc. Relationship of Exercise to Intake The source of dietary energy can be as important as the amount of energy in an athlete’s diet. Vitamins and minerals requiring special attention from athletes: B vitamins Antioxidant vitamins, such as vitamins C and E Iron Calcium The general proportion of energy for athletes and healthy individuals should be: 45-65% total energy from carbohydrates 20-35% from fat 10-35% from protein
Copyright 2010, John Wiley & Sons, Inc. Fluid Needs for Physical Activity During exercise, water is needed to eliminate heat, to transport oxygen and nutrients to the muscles and to remove waste products such as lactic acid from the muscles. The ability to dissipate heat depends on hydration levels. At rest in a temperate climate, an adult loses about 4½ cups of water per day through evaporation from the skin and lungs. Even with regular consumption, it may not be possible to consume sufficient fluid to remain properly hydrated. Failure to compensate for fluid losses can result in dehydration. If heat cannot be lost from the body, body temperature rises and exercise performance as well as health can be jeopardized.
Copyright 2010, John Wiley & Sons, Inc. Fluid Needs for Physical Activity Dehydration occurs when water loss is great enough for blood volume to decrease. Dehydration reduces the body’s ability to deliver oxygen and nutrients to muscles.
Copyright 2010, John Wiley & Sons, Inc. Hyponatremia
Copyright 2010, John Wiley & Sons, Inc. Heat-Related Illnesses
Copyright 2010, John Wiley & Sons, Inc. Recommended Fluid Intake
Copyright 2010, John Wiley & Sons, Inc. Food and Beverages to Maximize Performance
Copyright 2010, John Wiley & Sons, Inc. What Are You Getting From That Sports Bar?
Copyright 2010, John Wiley & Sons, Inc. Impact of Diet versus Supplements
Copyright 2010, John Wiley & Sons, Inc. Chapter 13 Copyright 2010 John Wiley & Sons, Inc. All rights reserved. Reproduction or translation of this work beyond that permitted in section 117 of the 1976 United States Copyright Act without express permission of the copyright owner is unlawful. Request for further information should be addressed to the Permissions Department, John Wiley & Sons, Inc. The purchaser may make back-up copies for his/her own use only and not for distribution or resale. The Publisher assumes no responsibility for errors, omissions, or damages caused by the use of these programs or from the use of the information herein..