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Chapter 18 Fitness and Health: Some Chemical Connections Daniel Fraser University of Toledo, Toledo OH ©2004 Prentice Hall Chemistry for Changing Times.

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Presentation on theme: "Chapter 18 Fitness and Health: Some Chemical Connections Daniel Fraser University of Toledo, Toledo OH ©2004 Prentice Hall Chemistry for Changing Times."— Presentation transcript:

1 Chapter 18 Fitness and Health: Some Chemical Connections Daniel Fraser University of Toledo, Toledo OH ©2004 Prentice Hall Chemistry for Changing Times 10 th edition Hill/Kolb

2 Chapter 182 Fitness in America Ready access to food –Especially in last 50–75 years More people do not perform manual labor –Do not burn as many calories Estimated that 61% of population is overweight –~26% in 2002 were obese

3 Chapter 183 Nutrition Require: fats, proteins, carbohydrates, vitamins, and minerals Get through balanced diet USDA recommends following the food guide pyramid USDA also encourages exercise

4 Chapter 184 Food Guide Pyramid

5 Chapter 185 Newer Food Guide Pyramid USDA currently trying to update food guide pyramid

6 Chapter 186 American Diet Consume too many calories –Average person should cut back Consume less fat –Especially saturated fats and trans fatty acids –Consume less partially hydrogenated vegetable oils Consume less red meat –Consume less fat and protein

7 Chapter 187 Vitamins and Minerals Vitamins: substances required by human body but cannot manufacture Minerals: inorganic elements that body needs Recommended daily allowance (RDA) –Excesses of any nutrient will be stored or excreted Example: excess turned into fat, not muscle

8 Chapter 188 Daily Reference Intake (DRI) Established amount required for males and females at different ages

9 Chapter 189 Nutritional Supplements Not required for healthy individuals eating a well-balanced and healthy diet Times requiring extra vitamins: rapid growth, pregnancy, lactation, and recovery from disease In small doses vitamins are nontoxic but, in large doses, they may be –Especially fat-soluble ones

10 Chapter 1810 A and B Vitamins Vitamin A: essential for vision, development, and skin maintenance –Can obtain from -carotene –Too much can increase risk of bone fractures later in life Vitamin B family –Many sources –No toxicity for B vitamins except B 6, may cause neurological problems

11 Chapter 1811 C and D Vitamins Vitamin C: essential to maintain collagen and immune system –Lack of it causes scurvy –Too much gets excreted Vitamin D: steroid-type vitamin –Promotes absorption of calcium and phosphorus –Too much may lead to formation of calcium deposits

12 Chapter 1812 Vitamin E Vitamin E: seems to have value in maintaining cardiovascular system Has anticoagulant properties Rats deprived of it suffer from sterility Protects against free radicals

13 Chapter 1813 Electrolytes Substances that conduct electricity when dissolved in water Sodium, potassium, and chloride ions are major electrolytes Need to be replaced Sports drinks probably needed only by endurance athletes

14 Chapter 1814 Water Best way to replace is to drink it Caffeine and alcohol are diuretics Thirst is delayed response –Drink on regular basis Lack of water can lead to heat stroke –Result of dehydration and overheating

15 Chapter 1815 Weight Loss Diets Cut out 100 kcal/day and keep normal activity –Lose 1 lb in 35 days –People seldom so patient Diets below 1200 kcal/day likely lead to nutritional deficiency –Body will slow down metabolism to conserve energy Cannot return to old habits once weight is lost

16 Chapter 1816

17 Chapter 1817 Example 18.1 Diet Calculations If you ordinarily expend 2200 kcal/day and you go on a diet of 1500 kcal/day, how long will it take to diet off 1.00 lb of fat? Exercise 18.1A A person who expends 1800 kcal/day goes on a diet of 1200 kcal/day without a change in activities. Estimate how much fat she will lose if she stays on this diet for 3 weeks. Exercise 18.1B A person who expends 2200 kcal/day goes on a diet of 1800 kcal/day and adds exercise activities that use 180 kcal/day. Estimate how much fat he will lose if he stays on this program for 3 weeks. Solution You will use 2200 – 1500 = 700 kcal/day more than you consume. There are 3500 kcal in 1.00 lb of fat, and so it will take 3500 kcal x ––––––– = 5 days 1 day 700 kcal (Keep in mind, however, that your weight loss will not be all fat. You will probably lose more than 1 lb, but it will be mostly water with some protein and a little glycogen.)

18 Chapter 1818 Crash Diets Quick = Quack Loss of water using diuretics –Weight comes back when body is rehydrated Low carbohydrate diets deplete body of glycogen: carbohydrate storage –1 lb glycogen has 3 lb water held to it –Replace when carbohydrates are consumed Crash diets tend to be low in some nutrients

19 Chapter 1819 Exercise Studies consistently show that people who exercise live longer –Sick less often and have fewer signs of depression Metabolic rate increases during exercise and stays higher several hours afterward Moderate exercise (<1 hr/day) does not cause an increase in appetite

20 Chapter 1820

21 Chapter 1821 Example 18.2 Exercise Calculations A fast game of tennis burns off about 10 kcal/min. How long would you have to play to burn off 1 lb of adipose (fat) tissue? Exercise 18.2A Walking a mile burns off about 100 kcal. How far do you have to walk to burn off 1 lb of fat? Exercise 18.2B A moderately active person can calculate the calories needed each day to maintain proper weight by multiplying the desired weight (in pounds) by 15 kcal/lb. How many calories per day do you need to maintain a weight of 120 lb? Solution One pound of adipose tissue stores 3500 kcal of energy. To burn it off at 10 kcal/min requires 3500 kcal x –––––– = 350 min 1 min 10 kcal It takes 350 min (5 hr 50 min) to burn off 1 lb of fat, even with a fast-paced game of tennis. (You dont have to do it all in one day.)

22 Chapter 1822 Level of Fitness Usually measures fatness Males require 3% body fat Females require 10–12% body fat Hard to measure accurately –Not indicated by weight or weight/height ratio

23 Chapter 1823 Measuring Fitness Estimate fat by measuring density of body –Fat less dense than muscle –Requires dunk tank Measure hip to waist ratio –Males <1 –Females <0.8 Using skinfold calipers – not accurate

24 Chapter 1824 Body Mass Index Attempts to measure fat in body BMI = 705 x body weight (lbs)/[height (in)] 2 BMI 18.5–24.9 average BMI 25–29.9 overweight BMI >30 obese

25 Chapter 1825 Example 18.3 Body Mass Index What is the BMI for a person who is 6 ft 2 in. tall and weighs 230 lb? Exercise 18.3A What is the BMI for a person who is 5 ft tall and weighs 120 lb? Exercise 18.3B What is the maximum weight, in pounds, that a person 5 ft 10 in. tall can maintain and have a BMI that does not exceed 25.0? Solution The persons height is (6 x 12) + 2 = = 74 in. BMI = –––––––– = x x 74 The body mass index is 29.

26 Chapter 1826 V O2 Max Maximum amount of O 2 a person can use per kilogram of body weight The higher, the better Requires complex equipment to measure accurately Limited by how fast muscles use oxygen and how fast O 2 can be transported to muscle

27 Chapter 1827 Chemistry of Muscles ~600 muscles in human body Heart most important one –Need to keep healthy Training effect: person who exercises regularly is able to do more physical work with less strain

28 Chapter 1828 Energy Conversion Energy currency in body is adenosine triphosphate (ATP) All food must be converted to ATP for use in muscles Use constantly for cell repair, nerve impulse, and body temperature regulation

29 Chapter 1829 Muscles Made of actin and myosin Work together when muscles contract Use ATP to contract

30 Chapter 1830 Exercise Aerobic exercise –Muscle contractions that occur in presence of O 2 –Typically during endurance events Anaerobic exercise – Insufficient O 2 available –Build up lactic acid, causing muscle fatigue –Oxygen debt: need O 2 to get rid of lactic acid Must be repaid –Typically during sprints and weight training

31 Chapter 1831 Muscle Fibers Two types, one for each type of exercise –Slow twitch: aerobic work –Fast twitch: anaerobic work

32 Chapter 1832 Building Muscle Endurance training increases myoglobin levels, respiratory capacity, and faster O 2 transport –Does not necessarily increase size of muscles Strength training increases size and strength of muscles –Does not necessarily increase respiratory capacity

33 Chapter 1833 Drugs and Athletics Restorative drugs: alleviate pain –Include painkillers, reduce swelling Stimulant drugs: try to improve performance –Include caffeine and amphetamines Anabolic steroids –Increase muscle mass more rapidly –Side effects: impotence, testicular atrophy, liver damage, growth of breasts, …

34 Chapter 1834 Exercise and the Brain With training, brain will produce endorphins –Natural painkillers May produce euphoric high during or after run –Runners may suffer withdrawal if they do not run regularly Regular exercise increases blood supply to brain

35 Chapter 1835 Smoking Associated with 24 different diseases Increases risk of stillborn babies

36 Chapter 1836 Chemistry of Sports Materials Tend to try to make sports equipment lighter and stronger –Large use of plastics

37 Chapter 1837 End of Chapter 18

38 Chapter 1838

39 Chapter 1839

40 Chapter 1840

41 Chapter 1841

42 Chapter 1842

43 Chapter 1843

44 Chapter 1844

45 Chapter 1845

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