Nutrition and Physical Fitness

1. Nutrition and Physical Fitness Chapter 16

2. Nutrition and Physical Fitness • Nutrition and physical fitness are essential interrelated parts of positive health promotion • Both reduce risks associate with chronic diseases

3. Nutrition and Physical Fitness • Both are important therapies in dealing with already developed chronic diseases • Health care workers should provide their patients with sound guidelines for physical fitness AND practice these guidelines themselves!

4. Nutrition and Physical Fitness • Objectives: • Describe physical activity and energy sources • Describe diet and exercise • Describe the planning of a personal exercise program

5. Nutrition and Physical Fitness • Key Concepts: • Healthy muscle structure and function depend on appropriate energy fuels and tissue-building material, as well as oxygen and water • Different levels of physical activity and athletic performance draw on different body fuel sources

6. Nutrition and Physical Fitness • A sedentary lifestyle contribute to health problems. Regular physical activity is an important part of a healthy lifestyle. • A healthy personal exercise program combines both strengthening and aerobic activities

7. Physical Activity Recommendations and Benefits • Guidelines and recommendations: • Increased participation in physical activity is a national health goal • Physical Activity = bodily movement that is produced by the contraction of muscle and that substantially increases energy expenditure. • Should be in addition to ADL • Exercise = planned, structured, and repetitive bodily movement done to promote or maintain one or more components of physical fitness

8. Physical Activity Recommendations and Benefits • Health Benefits – health problems may improve with moderate exercise • Coronary heart disease – exercise reduces risk by improving heart function, blood cholesterol levels, and oxygen transport • Heart muscle function: aerobic conditioning strengthens and enlarges this muscular organ, enabling it to pump more blood per beat • Blood cholesterol levels – raises blood levels of HDL, lowers blood levels of LDL • Oxygen-carrying capacity - increases

9. Physical Activity Recommendations and Benefits

10. Physical Activity Recommendations and Benefits • Health Benefits- • Hypertension – exercise is one of the most effective non-drug tx. for mild hypertension. • Exercise is an important adjuvant for those with higher BP along with medication

11. Physical Activity Recommendations and Benefits • Diabetes • For Type 2 DM – exercise increases glucose uptake in skeletal muscle despite insulin resistance. • For Type 1 DM – exercise must be balanced with food and insulin injections

12. Physical Activity Recommendations and Benefits • Health Benefits cont. • Weight management – exercise helps: 1.) regulate appetite 2.) increase BMR 3.) reduces the genetic fat deposit set-point level • Bone disease – Weight-bearing exercises help strengthen bones. The weight-bearing load increases calcium deposits in bone  increased bone density and reducing risk for osteoporosis • Mental health – exercise stimulates production of brain opiates – endorphins – which decrease pain and increase mood

13. Physical Activity Recommendations and Benefits • Types of Physical Activity • A good fitness plan is a combination of different enjoyable activities that most effectively reduce the risk of several chronic diseases • Activities of daily living – incorporate exercise into daily routine and perform it consistently • Resistance training – creates and maintains muscle strength • Aerobic exercise – increases oxygenation to all cells. E.g. walking – start slow and gradually increase the pace and distance

14. Physical Activity Recommendations and Benefits

15. Physical Activity Recommendations and Benefits • Meeting personal needs – In planning a personal exercise program, first assess an individual’s health status, present level of fitness, personal needs, and resources necessary. • Health status and personal gains – start slowly, build gradually to avoid discouragement and injury. Moderation and regularity. • Achieving aerobic benefits – raise the pulse to within 60% to 90% of maximum heart rate. • Maximum HR – subtract your age from 220

16. Physical Activity Recommendations and Benefits

17. Physical Activity Recommendations and Benefits • Exercise preparation and care – “warm up” • Stretch muscles to prevent stress or injury; cool down after exercise; don’t go beyond tolerance limits; rest when tired; stop when hurting; listen to your body!

18. Dietary Needs During Exercise • Muscle action and fuel • Structure and function – special cells and fibers making up muscle mass are stimulated by nerve endings to produce controlled muscle contraction and relaxation • Fuel sources – Muscle action requires fuel to burn for energy. Basic energy nutrients (CHO, fat); their metabolic products – glucose, glycogen, and fatty acids – provide ready fuel for immediate, short- and long-term energy needs

19. Dietary Needs During Exercise • Muscle action and fuel cont. • Oxygen – a person’s ability to deliver O2 to tissues for energy production determines how much exercise can be done. • “Aerobic capacity”– depends on: Body fitness and Body composition • Aerobic capacity is the body’s ability to deliver and use oxygen in sufficient quantities to meet the demands of increasing levels of exercise • Depends on the fitness of the lungs, heart, and blood vessels

20. Dietary Needs During Exercise • Aerobic capacity cont. • Body Composition – a person’s aerobic capacity depends on the percentage of body fat and lean muscle mass. (Body tissues that use more O2 make up the “lean body mass”.)

21. Dietary Needs During Exercise • Fluid needs – more water is necessary for increased activity and exercise • During exercise, body temp rises and heat is released in sweat  dehydration. • Water needs to be replaced as water or a glucose/salt drink

22. Dietary Needs During Exercise • Nutrient stores – with prolonged exercise, nutrient levels fall too low to sustain the body’s continued demands  fatigue, exhaustion. CHO and fat are the fuels used to maintain these energy reserves

23. Dietary Needs During Exercise • Fluid and Energy needs cont. • Energy – physical activity requires energy in the form of kcalories • Exercise is the only way to adjust an individual’s internal genetic set-point which determines how much body fat the person will carry naturally • This body fat set-point is raised (e.g. more body fat is stored) when the person becomes more sedentary • This point is lowered by regular exercise

24. Macronutrient and Micronutrient Recommendations • Nutrient ratios • Highly active people and some athletes have slightly increased protein requirements • CHO is the preferred fuel and is the critical food for an active person. • Recommended ratios: • CHO 45-70 % total kcals • Fat 15-25% total kcals • Protein 10-35% total kcals

25. Macronutrient and Micronutrient Recommendations • Carbohydrate – the major nutrient used for energy support during exercise • Comes from 1.) circulating blood glucose 2.) glycogen stored in muscle • 60-70% of daily energy intake for active persons should be from CHO • Complex CHO or starches are preferred because they breakdown more slowly and help maintain blood sugar levels more evenly, avoiding high and low blood sugar spikes

26. Macronutrient and Micronutrient Recommendations

27. Macronutrient and Micronutrient Recommendations • Fat – in the presence of oxygen, fatty acids serve as a fuel source from stored fat tissue • Total fat should not exceed 25-30% of total daily energy intake • Protein – insignificant contribution to energy • No more than the usual adult requirement is needed; approx 10%-35% of total daily kcals except for endurance and strength-trained athletes • Vitamins and minerals – cannot be used as fuel; exercise generally increases the body’s efficient use of vitamins and minerals • Some special requirements for athletes

28. Athletic Performance • General training diet – Athletes involved in heavy training are more susceptible to immunosuppression because of the extreme demands placed on the body. • A well-balanced diet with plenty of protein and CHO from a variety of foods helps prevent exercise-induced malnutrition and risk for injury and infection

29. Athletic Performance • Carbohydrate – endurance athletes have higher needs • Fat – moderate amounts needed • Protein – 10-35% of total kcals • Total energy – Athletes need varying amounts of energy, depending on body size and the type of training or competition involved

30. Athletic Performance • Competition • Carbohydrate loading – to prepare for an athletic event; a moderate, gradual tapering of exercise while total CHO intake is increased; usually a week before the event • Pregame meal – depends on the tolerance of the athlete; a light meal 3-4 hours before the event; high in complex CHOs • This gives the body time to digest, absorb, and transform the meal into stored glycogen

31. Athletic Performance Hydration – fluid needs depend on: • The intensity and duration of exercise • The surrounding temperature, altitude, and humidity • The level of fitness • The pregame or pre-exercise state of hydration • Athletes are advised (pregame) to drink more water than they think they need

32. Athletic Performance • Ergogenic aids – various substances that increase work or exercise capacity and output - e.g. use of steroids to increase muscle size, strength, and performance. (See p. 312 and 313 for list) • Are dangerous with serious physiologic side effects and psychological effects

33. Athletic Performance • Misinformation – manufacturers sometimes make distorted for false claims for products • Myths and Superstitions • Electrolyte solutions are always needed during exercise • A pregame meal of steak and eggs ensures maximal performance • Drinking water during exercise causes cramps