Week 1 AS Epidemiology PDF

Exercise Epidemiology KINESIOL 3H03 Dr. Jeremy Walsh Asynchronous Lecture #1 mcmaster.ca Lecture Outline Brief history of the evolution of exercise sciences Benefits of physical activity for health Evidence that in...

Exercise Epidemiology KINESIOL 3H03 Dr. Jeremy Walsh Asynchronous Lecture #1 mcmaster.ca Lecture Outline Brief history of the evolution of exercise sciences Benefits of physical activity for health Evidence that informs guidelines Defining & Measuring Exercise vs. Physical Activity Global physical (in)activity trends  Learning Objectives By the end of this lecture you should be able to… 1. Appreciate the historical roots of exercise sciences 2. Explain the difference between Physical Activity and Exercise 3. To examine the scientific evidence that informs physical activity guidelines Loading… 4. List the different approaches to measuring physical activity Identify the pros and cons of each approach 5. To evaluate global physical activity trends  How Did We Get Here? The Harvard Fatigue Laboratory (1927-1947) Part of Physiology & psychology of work Many workplace deaths / accidents Effects of fatigue, lighting, and temperature on worker productivity WWI – big lesson on the limits of human performance Exposure (cold/heat) Fatigue & Exhaustion Nutrition Loading… Source: https://www.hbs.edu/news/articles/Pages/historical-places-cool-spaces.aspx How Did We Get Here? Exhibit A: The Prison Treadmill Source: https://www.hfe.co.uk/blog/history-of-the-treadmill/  London Transport Workers Study Importance of Physical Activity 1949 – 1952 Compared rates of heart disease in bus drivers vs. ticket takers in London 31,000 people in total! Homogenous group Same work environment, hours, pay, etc. Different levels of physical activity Drivers had significantly higher incidence of heart disease compared to ticket takers Ticket takers had more mild forms of heart disease Findings confirmed in other occupations!  The Fitness Craze Is credited with the birth of the field of exercise psychology 1970’s & 80’s Source: http://content.time.com/time/covers/0,16641,19811102,00.html  Exercise vs. Physical Activity Physical Activity - Any bodily movement produced by skeletal muscles that expends energy beyond resting levels (>1.5 METs) Exercise – leisure time physical activity that is planned, structured, and repeated over time. (Caspersen et al., 1989) Movement Continuum Sleep ⟷ Sedentary ⟷ Vigorous Activity (ME T) Source: www.sedentarybehaviour.org  Loading… Source: www.eufic.org/en/healthy-living/article/9-proven-benefits-of-physical-activity  Physical Activity Improves Health The Evidence is Clear All Cause Mortality is the death rate in the population over a period of time Decreased Increased Kraus et al. 2019 Med Sci Sport Mortality Risk Mortality Risk Exer Physical Activity and Health Physical Activity Guidelines Kraus et al. 2019 Med Sci Sport Exer Physical Activity and Health Total PA Time > How PA Accumulated ( M What Matters More? o r Total physical activity time? t OR a How physical activity is accumulated? li t y Guidelines: ) >10 min bouts of PA… Emerging Research: This may not matter Saint-Maurice et al. 2018 J American Heart Brief Summary Physical activity (PA) is any bodily movement above 1.5 METs Exercise is a sub-category of PA… Leisure PA that is planned, structured, repeated Focus on PA as a health behaviour relatively recent Numerous health benefits of PA… lowers all cause mortality Guidelines = 150 min/wk of moderate-to-vigorous intensity PA At least 10 min per bout… but this recommendation change over time  Global Trends in Physical (In)Activity Men Globally, 1 in 4 adults do not meet the global recommended levels of physical activity 1.4B adults Up to 5 million deaths a year could be averted if the global population was more active People who are insufficiently active have a 20% to 30% increased risk of death compared to people who are sufficiently active More than 80% of the world's adolescent population is insufficiently physically active Women https://www.who.int/news-room/fact-sheets/detail/physical-activity Hallal et al. 2012  Lancet Global Physical (In)Activity Trends Worldwide, around 33% of women and 25% men do not meet activity guidelines Levels of inactivity are twice as high in high-income ♂ ♀ countries compared to low-income countries Consider: Why the discrepancy in PA between men and women? High income vs. lower income? Global Physical (In)Activity Trends Consider: Why regional differences? Trends across age-groups? How were measures taken?  Measuring Physical Activity or Exercise Physical Activity varies tremendously in: ◦ Mode (e.g. running, biking, weight training) ◦ Frequency (e.g. 3 days/week) ◦ Duration (45 minutes/session) ◦ Intensity (60% Max HR) 3 main approaches to measure PA / Exercise: 1. Subjective measures (self-report/survey) 2. Objective Measures (tracking devices, fitness apps, direct measurement) 3. Observation  Measuring Physical Activity or Exercise Subjective Measures Self-report/survey ◦Log (weight training) ◦Physical activity recall questionnaires Self-Report of Physical Activity Behavior Godin Leisure-time Exercise Questionnaire COPYRIGHT © HOLCOMB HATHAWAY, PUBLISHERS  Measuring Physical Activity or Exercise Objective Measures ◦ Heart rate monitor ◦ Pedometer ◦ VO2 measurements ◦ GPS / fitness apps ◦ Accelerometer “gold standard” Worn on body (wrist/thigh) → measure movement in three dimensions/planes  Measuring Physical Activity or Exercise Observation Direct ◦ View a fitness class or watch kids at play to measure intensity Indirect ◦ Take attendance to measure adherence  Brief Summary 3 main approaches to measure PA / Exercise: 1. Subjective measures (self-report/survey) 2. Objective Measures (tracking devices, fitness apps, direct measurement) 3. Observation