Epidemiology, Physical Activity, Exercise, and Health

Transcription

1 Chapter 1 Epidemiology, Physical Activity, Exercise, and Health Prepared by: Richard C. Krejci, Ph.D. Professor of Public Health Chapter

2 What You Will Learn in this Chapter How to apply scientific method to exercise physiology to improve your critical thinking & decision-making skills What the field of epidemiology has to do with promoting health & exercise messaging for the United States & international communities Basic terminology related to epidemiology, physical activity, exercise, & health Measurement of exercise & surveillance in epidemiology How to promote positive behaviors associated with recommended programs of exercise related to Health/Fitness, Sports Medicine, Athletic Performance, & Rehabilitation

3 Introduction to Epidemiology, Physical Activity, Exercise, and Health Exercise physiology is the study of: 1. Functional changes that occur in response to a single session of exercise 2. Adaptations that occur as a result of regular, repeated exercise sessions

4 Exercise Science Research Integration & coordination among most body systems, including Muscular-skeletal Nervous Circulatory Respiratory Immune Endocrine (hormone producing) Digestive Renal Integumentary (skin) Reproductive systems

5 Basic Definitions Physical activity (PA) Any movement that works larger muscles of body Arm, leg, & back muscles Engaging in physical activity causes one to: Expend energy or kilocalories (calories) vs remaining sedentary Examples: dance, yard work, cleaning, etc. Exercise Planned, structured, & repetitive workout Results in an outcome Improvement in personal fitness

6 What Is Physical Fitness? Definition The ability to respond to routine physical demands, with enough reserve energy to cope with a sudden challenge.

7 The Five Components of Health Related Physical Fitness 1. Aerobic and Cardiorespiratory Endurance 4. Flexibility 5. Body Composition 2. Muscular Strength 3. Muscular Endurance

8 The Six Components of Skill Related Fitness (Motor-Skill, Athletic, or Performance-Related Fitness) Agility Balance or equilibrium Coordination Power Reaction time Speed or velocity

9 Functional Health and Longevity Low Minimum National US Recommendations High Sedentary Lifestyle Physical Activity Exercise Program Inherent factors: genetics, health status, environmental factors

10 Functional Health Maintain high levels of health & wellness by reducing or controlling one s health risks for development of health problems Maintaining one s physical movement independence to perform Functional abilities Activities of daily living (ADL) Critical factor as we age Requires MVPA, healthy diet, and avoiding harmful substances

11 The Scientific Method Systematic process for testing hypotheses Five steps in the simple scientific model 1. Develop a sound question 2. Observe the situation related to the question 3. Describe what you observe 4. Comment on observations and descriptions 5. Predict future outcomes related to the question

12 Suggestions for Effectively Applying the Scientific Method First step Think about the way a question is asked Next step Decide how to gather the best scientific evidence to help you determine the answer

13 Suggestions for Effectively Applying the Scientific Method Need to use following 3 levels of scientific evidence to make more informed decisions: 1. Strong scientific evidence from many published research reports in credible scientific journals consensus (e.g. Medicine and Science in Sport and Exercise). 2. Best scientific evidence that we can find based on fewer reports than found at level one in published literature 3. Expert opinion (be careful)

14 Epidemiology Study of how a disease or health outcome is distributed in populations & what risk factors influence or determine this distribution Epidemiologists study infectious or communicable diseases Influenza or tuberculosis Heart disease Cancer Behaviors that may positively or negatively impact those chronic diseases

15 Exercise Physiology and Functional Health Individuals who remain physically active Maintain their weight Abstain from smoking as they age Maintain their functional fitness levels longer than those who do not Fig 1.5 p. 10

16 Exercise Prescription A dose response relationship exists between Amount of exercise you prescribe for a client Health outcomes for that client Dose effects of exercise provide varying acute & long-term physiological benefits that can influence: Physical fitness Health outcomes

17 Health and Fitness Benefits Based Upon Lifestyle and Physical Exercise This diagram summarizes the difference in the overall level of benefit between attaining a health fitness standard versus a high fitness standard. It is important to make this distinction as you interpret your personal fitness test scores in the first lab.

18 The Maintenance of Functional Health Fig 1.8 p. 13

19 Risk of Dying Prematurely For most health benefits Individuals should acquire 150 min of PA per week To achieve higher performance goals Most clients need to exercise more ( min/wk) Sometimes at higher intensities to be successful Fig 1.9 p. 14

20 Rate of Perceived Exertion (RPE)

21 Defining Exercise Table 1.4 p. 14

22 Examples of Moderate to Vigorous Activities Type Children Adolescents Table 1.5 p. 15

23 General Exercise Guidelines (Tables p. 16) Children and adolescents Adults Older Adults

24 Sedentary Lifestyle Risk Factors An inactive person throughout life has an increased risk for: High blood cholesterol and triglyceride concentrations Cardiovascular disease Hypertension Low back pain Osteoporosis Obesity Diabetes Negative emotional stress Colon cancer

25 Smoking Chronic smokers have an increased risk for Heart & lung disease compared with nonsmokers Smokers 2x as likely as nonsmokers to have a heart attack Smokers tend to be Less active than nonsmokers Which increases their risk for premature chronic disease

26 Smoking Smokers who stop smoking & choose an active lifestyle can Reduce their heart attack risk to that of nonsmokers in 2 to 3 years Although it is very difficult to stop smoking It is never too late to quit smoking Begin a more active lifestyle Summer jobs at CC!

27 Hypertension A person with high blood pressure (BP) is at an increased risk for Stroke (damage to brain) Heart attack Kidney disease Other serious health problems Hypertension has few symptoms This is one reason why it can be so dangerous Also known as silent killer

28 Hypertension Hypertension is associated with Genetic makeup Aging High salt or sodium intake Obesity Excessive alcohol consumption

29 High Levels of Cholesterol and Triglycerides A person with an increased [cholesterol] in blood is at an increased risk for Development of atherosclerosis Total amount of cholesterol in blood is determined by combination of Fats consumed (especially saturated fats) Fats produced by our bodies (especially cholesterol)

30 Elevated Blood Lipids High-density lipoprotein (HDL) Good cholesterol Higher amounts are associated with a lower risk for heart disease (> 60 mg/dl) Low-density lipoprotein (LDL) Bad cholesterol (> mg/dl) Very low-density lipoprotein (VLDL) Bad cholesterol Higher amounts of LDL & VLDL are associated with higher heart disease risk

31 Triglycerides High [triglycerides] in blood are associated with Greater heart disease risk (>150 mg/dl) Therefore, it is important to: Limit fat intake in the diet Maintain desired body weight (exercise/diet) Take lipid medications as prescribed by a physician

32 Type 1 Diabetes Initially thought to be a genetic disease However, Type 1 diabetes has been diagnosed People of all ages Causes immune system to attack & destroy insulinproducing beta cells of pancreas Treatment Insulin

33 Gestational Diabetes Pregnancy also appears to increase Risk for Type 1 diabetes after birth Particularly for women who become pregnant after age 35

34 Type 2 Diabetes Formally called adult-onset diabetes Initially linked to excessive weight gain Causes insulin resistance at tissues Slows down or inhibits glucose uptake Used to be seen only in Adults older than 40 years However, recently, as many as 50% of new Type 2 diabetic cases are seen in children and adolescents.

35 Type 2 Diabetes Type 2 diabetes is linked to: Lack of physical activity Being overweight Increased waist circumference Genetic factors predisposing individual to obesity

36 Diabetes Can lead to premature health problems: Diabetic ulcers Limb gangrene Limb amputation Blindness Renal nephropathy Kidney failure Requires renal dialysis & transplantation

37 Body Composition Person with too much body fat (BF) is at an increased risk for problems such as: Hypertension Heart disease Type 2 diabetes Increased body weight (overweight: BMI > 25) & obesity: BMI > 30) often Begins in childhood Usually persist into adulthood unless person Alters his or her diet Adopts an active lifestyle

38 Changes in Prevalence of Obesity

39 Stress Physical & psychological responses of your body as you try to adapt to stressors Stressor Anything that requires you to adapt & cope with either positive or negative situations

40 Distress Defined as Excess negative stress Caused by fear, anger, confusion, or other similar mood states in one s life Can increase risk for chronic diseases Such as heart attack Make a disease or illness process worse

41 Eustress Defined as Positive stress Though to be health promoting An enjoyable and challenging type of stress, such as: Feelings prior to becoming elected class president Scoring well on an exam Obtaining your driver s license

42 Non-Modifiable Risk Factors: Age Older person tends to be at increased risk for diseases such as High BP, heart disease, & cancer compared to younger individuals However, a chronic disease process can Exist without evidence of symptoms in childhood or early adulthood Not manifest itself until later in life Ages 70, 80, 90, & beyond

43 Non-Modifiable Risk Factors: Sex Men between ages of 40 & 50 have Greater risk for heart disease than do women of same age range Risk for heart disease for women increases dramatically After onset of menopause (usually age 50 55) Then matches that of men

44 Reducing Risk for Osteoporosis Many women Take calcium supplements Exercise regularly to modify & reduce that risk Exercise regimen for both women & men should include: Weight training To help maintain bone health

45 Non-Modifiable Risk Factors: Heredity A person may be born with Genetic predisposition to increased health risk for various disease processes For example: Some individuals are born with Extremely high blood [cholesterol] They may develop Atherosclerosis at an early age (in 20s or 30s) May cause heart attacks Die prematurely

46 What Are Three Primary Factors That Influence One s Health and Longevity? Genetics Environment Health & Longevity Behavior

47 Homeostasis Maintenance of a relatively stable internal environment at rest It s essential for survival of each cell in the human body contributes to maintenance of body s internal environment shared by all cells

48 Negative Feedback and Homeostasis Fig 1.17 p. 24

49 Steady State Exercise Body s ability to Maintain homeostaticlike conditions during movement (exercise) Graph shows VO 2 response of an individual who attempts to jog at 50% of their maximal ability

50 Steady State Exercise Ability to obtain a steady state during exercise Cannot be achieved at high intensities of exercise (>90% of maximum effort) However, a normal response to exercise training is to obtain a steady state sooner

51 Epidemiological Research and Its Relationship to Exercise Accuracy of information gathered depends on following nine key criteria: 1. Validity: Degree to which an instrument measures what it is supposed to measure 2. Reliability: Ability to obtain repeatable results during different testing sessions 3. Sensitivity: Ability of method or assessment tool to measure & detect change in exercise patterns 4. Mortality: Death (number or rate) 5. Morbidity: Rate of incidence of a disease

52 Key Criteria Continued 6. Incidence: Rate or range of occurrence (e.g. new cases within a given period of time) 7. Prevalence: Total number of cases of a disease in a given population at a specific point in time 8. Biological plausibility: Theory that there is a causal link between preventable diseases or health outcomes & exercise 9. Confounders: Variables, such as age, body composition, or baseline health status, which might influence interpretation of the data

53 Two Basic Types of Epidemiologic Studies 1. Observational: A study that evaluates self-selected intensities of exercise by study subjects & often does not control for confounders that might influence the conclusions made by the researcher 2. Experimental: A study where researcher can assign individuals to groups of exercise or control (inactivity) & various confounders can be statistically controlled Randomization: process by which Individuals or groups are assigned by chance (to avoid discrimination)

54 Objective Methods of Measuring Exercise Participation and Energy Expenditure Direct observation Indirect calorimetry Doubly labeled water (isotopes) Global positional systems (GPS) Heart rate monitor Accelerometers Pedometers Physical fitness assessments

55 The End Slide show was developed by: Richard C. Krejci, Ph.D. Professor of Public Health Columbia College (SC)