Nutrition for Health, Fitness & Sports Performance Lecture 1 PDF

Nutrition for Health, Fitness and Sports performance Summer 2021  Physical fitness = set of abilities individuals possess to perform specific types of PA.  Health-related fitness = healthy body weight and composition + CV – respiratory fitness + adeq...

Nutrition for Health, Fitness and Sports performance Summer 2021  Physical fitness = set of abilities individuals possess to perform specific types of PA.  Health-related fitness = healthy body weight and composition + CV – respiratory fitness + adequate muscular strength + muscular endurance + sufficient flexibility.  Physical activity (PA) = any bodily movement caused by muscular contraction that results in the expenditure of E.  Unstructured PA = includes usual activities of daily living – not planned.  Structured PA = planned program of PA designed to improve physical fitness (= exercise).  Basic Principles of exercise training  Overload = basic principle that represents intensity, duration and frequency.  Progression = increasing of the overload as the body adapts to the exercise.  Specificity= specific adaptations the body makes in response to the type of exercise and overload.  Recuperation = recovery time in which the body rests after exercise.  Individuality = effect exercise will have on each given individual, as determined by genetic characteristics.  Reversibility = disuse = without ex, body will begin to lose adaptations it has made over the course of the exercise program (“use it or lose it”).  Overuse = excessive amount of ex that may induce adverse health effects.  Role of exercise in health promotion  Health benefits of PA:  Prevent and reduce the risk of many diseases (BP, DM II, heart disease, stroke, breast and colon cancer…).  Improve self-image.  Reduce mental depression and delay onset and severity of Alzheimer’s disease.  Reduce risk of falls in elderly.  Improve bone health and immune function.  Reduce arthritis pain.  Improve quality of sleep and of life and increase longevity. What is exercise? A physical activity that is performed for the purpose of either improving, maintaining, or expressing a particular type(s) of physical fitness. eg: training for or performing athletics, sports, or recreational activities such as jogging, roller blading, ice skating, swimming, etc.  So all exercise is physical activity, but not all physical activity is exercise. Why Exercise?  Cost of physical inactivity over the time:  Short-term : metabolic deterioration and weight gain.  Intermediate – term : increase in disease.  Long-term : increased premature mortality.  Fitness as prevention is effective and inexpensive compared to medical treatment for disease “Exercise is the closest thing we’ll ever get to the miracle pill that everyone is seeking. It brings weight loss, appetite control, improved mood and self-esteem, an energy kick, and longer life by decreasing the risk of heart disease, diabetes, stroke, osteoporosis, and chronic disabilities.” [ H. Atkinson. Exercise for Longer Life:The Physicians Perspective. HealthNews 7, no. 3 (1997): 3] Benefits of exercise  Prevent and reduce joint problems  Reducing wt. decreases joint wear and tear.  Exercise helps prevent arthritis.  Exercise keeps muscles, bones and cartilage strong and healthy protecting joints.  Benefits of exercise  Halt Bone Loss  Older age makes both men and women more prone to bone loss but exercise can increase both bone mass and strength.  Increased bone mass helps prevent fractures and osteoporosis. Benefits of exercise  Improved Respiration  During exercise lungs have to work harder to supply oxygen to the body. Lungs adapt to the extra workload and become more efficient at providing oxygen. Eventually, exercise and other daily activities become easier. Benefits of exercise  Cardiovascular Disease  Exercise reduces blood pressure which is the main cause of heart attack.  Exercise prevents atherosclerosis by reducing cholesterol plaques that clog arteries and can lead to stroke and or heart attack. Benefits of exercise  Cancer  Exercise helps prevent obesity which is a major risk factor for several types of cancer.  Colon Cancer: Physical activity speeds movement of food through GI tract.  Breast Cancer: High levels of estrogen influence development of CA of female reproductive system and exercise reduces circulating estrogen. Benefits of exercise  Diabetes  Exercise increases ability of body to use insulin.  Exercise removes glucose directly from blood to use for energy during activity.  Exercise controls body wt. which may decrease risk of diabetes development or progression.  Reduce risk of CVD. Benefits of exercise  Depression  Exercise just as effective as antidepressant meds for treatment of depression.  HOW? Reduces health problems, improves sleep pattern and controls wt thus enhancing self esteem.  Exercise stimulates endorphin production. Endorphins relieve pain by activating opiate receptors. They are involved in determining mood and controlling response to stress. Prolonged exercise above 70% VO2 max contribute increased production of endorphins resulting in sense of euphoria labeled “runner’s high”. Benefits of exercise  Brain  Boost alertness (by epinephrine and norepinephrine release).  Improve memory.  Improve intellectual function.  Reverse age-related decline in mental function and loss of short-term memory.  How does exercise enhance health ?  In general, PA involves changes in gene expression that modify cell structure and function.  Most body cells can produce and secrete small protein known as cytokines:  Myokines (muscle cells).  Adipokines (adipose cells). Ex induced cytokines effect on genes reduce many of the risk factors associated with the development of chronic diseases (secretion of anti-inflammatory cytokines).  Other health promoting mechanisms:  Decrease fat ➔ decrease production of unhealthy cytokines and decrease estrogen levels.  Decrease in abdominal obesity ➔ decrease in BP and serum lipids levels.  Increase in bone density.  Increase number of glucose receptors in fat cells ➔ improve insulin sensitivity. Do most of us exercise enough?  In general, NO.  Most adults are not getting enough physical activity.  About 40-50% of college students are physically inactive.  Children and adolescents more physically active, but many not obtaining adequate amounts  Increased type 2 diabetes in children is related to physical inactivity.  How much PA is enough for health benefits ?  Comprehensive program of physical activity:  Increase daily unstructured PA.  Increase daily amount of structured PA:  Aerobic: 30 min, 5 times/week of moderate intensity. 20 min, 3 days /week of vigorous intensity.  Resistance: 8-10 ex that stress major muscle groups 8-12 repetitions of each ex at least twice a week.  Flexibility and balance: 2 days/week at least 10 min daily. According to some scientists, more than 60 min of daily aerobic exercise is needed to induce weight loss and maintain a healthy body weight!!  Can too much ex be harmful to my health ?  In general, the health benefits far outweight the risks of ex.  However ex, particularly when excessive and in individuals with pre-existing health problems, may increase risk of the following problems:  Orthopedic problems (stress fractures).  Impaired immune function (Excess may decrease immunity so higher susceptibility to illness).  Exercise-induced asthma (Anaphylaxis).  Osteoporosis (Weight loss and menstrual irregularities leading to loss of bone mass).  Heat illness and kidney failure (Stress and dehydration from exercising in heat could cause muscle damage that may result in kidney failure).  Heart attack (Acute bout of vigorous activity can increase risk of myocardial infarction and sudden cardiac death in those who are habitually inactive). General guidelines for exercise  Level I: 30 minutes daily: low-intensity  Level II: 3-6 days/week, > 20 minutes at 50-85% increase in heart rate  Level III: 3-7 days/week stretching to fitness  Level IV: 2-3 days/week resistance activities  Level V: physical inactivity (e.g. TV watching) The type, amount and intensity of exercise that produces many of these benefits is well within the capacity of most people. There are strong synergistic health-promoting effects among physical activity, good nutrition, leaness, not smoking, and other simple health-promoting behaviors.  Humans are designed to be active on a daily basis.  Thus, optimal health and fitness can only be achieved by people who are active on most days.  Being active is the normal or natural way of living - modern economies engineer most activity out of our lives.  Sedentary people can benefit from relatively small amounts of activity (adding > 30 minutes/day of moderate intensity activity).  But you don’t get something for nothing! There appears to be a favorable dose-response across a wide range of activity.  If a small amount of activity is good - more activity is likely better (especially for outcomes like weight control). Sports-related fitness Exercise and nutrition What is Sports Nutrition?  A relatively new area of study involving the application of nutrition principles to enhance sports performance  Application of eating strategies to promote good health and adaptation to training, recover quickly after each exercise session and to perform optimally during competition. Do we eat right?  Too many Calories  Too much fat and saturated fat  Too much sugar and other sweeteners  Too much salt  Too much meat and cheese  Too few fruits and vegetables  Too few fiber-rich foods  In general, more than we need and less of what we need more How important is nutrition to athletic performance?  Ability to perform depends upon 2 factors???????  Genetic endowment  State of training  When everything is equal, nutrition can make the difference between winning and losing Ergogenic aids and sports performance: Beyond training  What is an ergogenic aid ?  Ergo= work  Gen= production of  Usually defined as « to increase potential for work output ».  Mechanical aids: used to increase E efficiency (eg: light weight racing shoes).  Psychological aids: increase mental strength (eg: hypnosis).  Physiological aids: increase physical power (eg: blood doping).  Pharmacological aids = drugs (eg: steroids).  Nutritional aids= nutrients (eg: protein supplements).  The most used ergogenic aids are dietary supplements. Dietary Supplements N.B: A dietary supplement is a food product, added to the total diet, that contains at least one of the following ingredients: a vitamin, mineral, herb or botanical, amino acid, metabolite, constituent, extract, or combination of any of these ingredients  Are nutritional ergogenics safe & legal ?  Over-the-counter dietary supplements appear to be safe for the general population when taken in recommended dosages.  FDA has noted that some sports supplements contain chemicals that have been linked to numerous serious illnesses and even death.  The product label may not contain all the ingredients or may contain ingredients not listed.  Concerning legacy:  The use of pharmaceutical agents to enhance performance in sport has been prohibited by the governing bodies of different sports.  Use of drugs in sports is known as doping.  Essential nutrients are legal for use. Most food substances and constituents are also legal. Other dietary supplements such as DHEA are prohibited.