Physical Activity Epidemiology

1. Physical Activity Epidemiology By Jenna Kannenberg, Kara Burger, and Kathy Cassidy

2. Epidemiology “The study of the distribution and determinants of health-related states or events in specific populations, and the application of this study to the control of health problems” In other words… Epidemiology helps us understand how disease spreads through a population

3. Epidemiology is used in 4 ways: 1. To establish a cause - To better understand the causes of chronic diseases, epidemiologists use a model called ____________________. pg. 195 2. To trace the natural history of a disease to understand its normal cause and how it progresses 3. Describe the health status of an entire population to determine the burden of the disease in that population 4. Test interventions to determine the success or failure or programs established to prevent or treat the disease.

4. Physical Activity epidemiology Defined as: ________________________________________________________________________________________________________________________ ____________________________________. Diseases and conditions thought to be associated with a sedentary lifestyle include: Cardiovascular disease Type Two Diabetes Cancer Osteoarthritis Obesity Mental illness

5. Importance of physical activity epidemiology Physical Activity epidemiology is one of the newest subdisciplines of exercise science, but has earned national recognition in recent years owing to evidence that physical inactivity is a major risk factor for a number of chronic diseases

6. Exercise and physical activity Physical Activity: ____________________________________________________________________________________________________________. Exercise is considered a specific subcategory of physical activity, defined as: ________________________________________________________________________________________________________________________________________________.

7. Total energy expenditure Total Energy Expenditure: the total amount of energy, expressed in kilocalories, expended each 24-hr period. Components of Total Energy Expenditure: 1. 2. 3.

8. Total energy expenditure Physical Activity is the most variable component of total energy expenditure and is divided into two parts: 1. __________________________________________________________________ 2. __________________________________________________________________

9. Epidemiology Terminology The primary goal of epidemiology is to identify the determinants of disease to decrease mortality and morbidity with a population. Morbidity is defined as: _______________________________________________________________________________________________________________________________________________.

10. Epidemiology terminology Physical activity epidemiology applies the results of scientific research to the prevention and control of diseases and conditions within populations for the purpose of promoting health. The measurement of the amount of disease in a population is expressed as various rates.

11. Epidemiology terminology A rate is: A fraction that consists of a ___________ and a __________. The ___________ is the number of people from a population with the disease, and the ___________ is the number of people in the entire population. Rates of death are called __________________, and rates of individuals with the disease are called __________________.

12. Epidemiology terminology Example: In a population of 100,000 people, 500 people are affected by the disease. To find the morbidity rate, take 500/100,000= .005(shown as a ratio) or 0.5%. So therefore; the morbidity rate is 0.5% or 5 per 100 people.

13. Epidemiology terminology _________________ are estimates of the number of individuals within a population without a disease who develop that disease during a specific time period. _________________ are estimates of the number of people who already have the disease in a population at a particular point in time or during a given time period.

14. Epidemiology terminology ___________________ is the facts that a hypothesis and the relationship that is proposed are in harmony with existing scientific information. Biologic plausibility is a key piece of sound epidemiology research.

15. Epidemiology terminology __________ is used to quantify the degree to which chance may account for an association observed in a particular study. ________________ indicates that the results of a particular study were not caused by chance or some other random variable. ________________ is a variable with an effect that is entangled with the effect of physical activity.

16. Assessment of Physical Activity and Exercise in Epidemiology Studies __________________- A subjective recall of the activity engaged in over a specific time period. Most Common Because __________________ __________________ __________________ __________________

17. Assessment of Physical Activity and Exercise in Epidemiology Studies Examples of objective measures used in epidemiology research. -Total energy expenditure -_________________________ - Movement counters -__________________________ - Measures that measures physical fitness -__________________________ - Field Tests and other observations

18. Assessment of Physical Activity and Exercise in Epidemiology Studies The assessment tool must elicit accurate information on the types of physical activity that encompassed the greatest proportion of energy expenditure in the population of interest. _________________ are important when assessing younger and healthier populations.

19. Assessment of Physical Activity and Exercise in Epidemiology Studies Different dimensions of physical activity. -_____________________ -_____________________ -_____________________ -_____________________ -_____________________

20. Assessment of Physical Activity and Exercise in Epidemiology Studies Questionnaires do not reflect total energy expenditures of an individual. Why? Questionnaires are helpful because the results are relative distributions that can be examined in relation to disease outcome.

21. Assessment of Exercise and Fitness in Epidemiology Studies When examining population studies there is only a ____________ relationship between physical activity and physical fitness. This indicates other factors involved such as ____________________________________.

22. Epidemiology Study Designs ___________________ - most expensive, most conclusive, most powerful. ___________________- more popular, less conclusive.

23. Experimental Study Design _________________- most powerful labor intensive epidemiologic study design. - efforts are made to prevent or delay onset of disease in question by manipulating the risk factor of interest.

24. Observational Study Designs __________________- collect information about the health outcome and the potential risk factor within the same group at the same time. __________________- individuals with and without the disease of condition of interest are asked questions about their past.

25. Observational Study Designs __________________- strongest observational study, identifies and follows individuals initially free of the health outcome of interest and seeks to establish if initial of subsequent physical activity levels differentiate those who do and do not develop the disease

26. Prospective Studies in Diabetic Women Study of inactive and active women over time to determine if physical activity levels play a role in determining who will and will not develop type 2 diabetes 87,253 non-diabetic female registered nurses; 34-59 years “At least once a week do you engage in regular activity similar to brisk walking, jogging, bicycling, etc, long enough to work up a sweat? If yes, how many times per week?” Results: -Vigorous physical activity at least once a week= lower incidence of self-reported type 2 diabetes and were leaner than women who did not exercise once a week -*Individuals who are relatively more physically active are less likely to develop type 2 diabetes

27. Prevalence of Sedentary Behavior in the U.S. -Inactive for most of the day, with little or no exercise -Incorporating physical activity into a day’s activity has become less of an automatic occurrence and more of a planned behavior Cars, elevators, tv sets, etc. replace human effort -Behavioral Risk Factor Surveillance System (BRFSS): ____% of U.S. adults do not engage in any leisure-time physical activity at all. The prevalence of sedentary behavior is even higher in the U.S. minority populations.

28. National Efforts -The U.S. Centers for Disease Control and Prevention (CDC) and the American College of Sports Medicine (ACSM) came together in early 1993 to develop a clear public health message regarding physical activity -They came up with a revision of the old exercise recommendations in an attempt to clear up the public misconception that one must engage in vigorous, continuous exercise in order to gain any health benefits. -Old recommendations: designed for the athlete; exercise meant high levels of intensity and was associated with gyms, exercise equipment, and sweat. -New recommendations: each and every individual could be more active *Sedentary individuals can increase their levels of _________ physical activity, such as walking.

29. Objectives for Increasing Physical Activity and Fitness by the Year 2000 -Increase to at least 30% the proportion of people aged 6+ who engage regularly, preferably daily, in light to moderate physical activity for at least ____________. -Reduce to no more than 15% the proportion of people aged 6+ who engage in no leisure-time physical activity. -Increase to at least ____% the proportion of people aged 6+ and older who regularly perform physical activities that enhance and maintain muscular strength, muscular endurance, and flexibility. -Increase to at least 50% the proportion of overweight people aged ______________ who have adopted sound dietary practices combined with regular physical activity to attain an appropriate body weight

30. Old vs. New exercise recommendations Old: Frequency: 3-5 days per week Intensity of training: 60-90% maximal heart rate Type: activities that require the rhythmical and aerobic use of large muscle groups Time: 20-60 minutes per training session New: ______or more minutes of __________ intensity physical activity on most days; either in a ingle session or accumulated in multiple bouts.

31. How much physical activity is enough? -Many of the overall health benefits can be gained by performing activities that are not necessarily of high intensity. -Research suggests that individuals engaging in a _________level of physical activity have a ________risk of many chronic diseases compared to sedentary individuals. -Significant differences in risk of diabetes and coronary heart disease appear to occur between individuals who report relatively no physical activity or exercise and those who report doing something. -There is a decrease in mortality rates in originally healthy individuals as you move from the least fit to the most fit groups.

32. Mortality Rates and Coronary Heart Disease -12,138 middle-aged men participating in the Multiple Risk Factor Intervention Trial were studied- all at high risk for CHD. At the baseline of the study, these men were all free of disease. -Researchers obtained the subjects’ levels of leisure physical activity (low, moderate, and high physical activity) and followed them for 7 years. Results -The major decrease in mortality rates existed between the men who were part of the low activity group at baseline and the two more active groups (low activity group compared to moderate and high activity groups.) -No apparent difference between the 2 more active groups of men (moderate and high activity groups) -*Most of the protective effect of physical activity in the prevention of CHD occurs between those engaged in moderate to high levels of physical activity and those that are the least active.

33. The Challenge -In 1993, the National Institutes of Health (NIH) sponsored a physical activity and health workshop titled “Disease Prevention Research at NIH: An Agenda for All.” -Recommendations were made regarding future physical activity research directions: there were 3 key recommendations: 1. The type, pattern, intensity, frequency, and total amount of physical activity required to provide physical health benefits should be _______ and _______. 2. Identify variations in dose-response relationships between different populations. 3. Develop strategies to ___________________________ throughout the U.S. population. *These 3 challenges are still the most important issues in the field of physical activity epidemiology today. *There is still tremendous difficulty helping the sedentary to become more active and maintain that active behavior. Therefore, additional research is needed.

34. Summary -__________________ is a field of research that investigates the relationship between physical activity and health and diseases in a population. -Some of the most frequently used methods used in physical activity epidemiology include _________________, the doubly-labeled water technique, and ___________________. -The experimental study design is favored because it is the most powerful and most conclusive. Because experimental studies are expensive, ___________ studies are more widely used to observe the occurrence of the disease or condition in individuals who differ by the factor of interest. -The surgeon general’s report of 1996 exemplified the importance of the positive effect of physical activity on public health. -3 of the most important issues of future research in the field of physical activity epidemiology are _________ and _________the amount of physical activity required to provide health benefits __________ ___________in dose-response relationships between different populations ___________ ____________to promote long-term increases in physical activity throughout the U.S population.