PH physical activity


Integrating Public Health and Physical Activity Chapter 3

In this chapter we will be learning about the history of physical activity and public health, how science is translated into practice in physical activity and public health, and how the application of scientific findings differentiates physical activity and public health from other areas such as medicine and exercise.


Physical Activity and Public Health

Field of study that looks at the health effects and risks of physical activity and ways to help people become active and maintain a healthy level of activity throughout their lives

Public health is the study of preventing diseases and promoting health, more precisely promoting health of community and populations. Integrating physical activity in public health is an area of study where the health effects of physical activity is measured and the ways of physical activity initiation and maintenance is researched.


History of PA and Public Health

Dr. Jeremy N. Morris (1953 Study)

Studied heart disease and consequences among workers employed by the London transport system

Result showed physically active conductors had significantly lower rates of CHD than the less active drivers

Physical activity for health concepts started to evolve.

The formal study of physical activity is much newer though the concepts had originated long before. Early 1900 and 20th century witnessed the growth of exercise science and expansion of personal physical education. Epidemiology, the basic field of public health also advanced in the 20th century. The field of exercise science and public health came closer by a study which was done on 1953 in London. An Epidemiologist named Jeremy N. Morris conducted a study on workers of the London transportation system to observe causes and consequences of heart diseases. He was particularly interested in seeing the amount of physical activity men get as course of their jobs and how that relates to risk of heart diseases. Dr. Morris looked at the bus drivers who were basically inactive as they were sitting and driving the bus and the bus conductors who were more active as they were walking up and down all the time to collect the tickets form the bus riders. Interestingly, the connection between coronary heart disease and physical activity idea evolved through this research as Morris found out physical active bus conductors were less likely to have coronary heart disease than less active bus drivers. The studies published by Dr. Morris on occupational physical activity, is viewed today as the grandfather of physical activity and health.


History of PA and Public Health

Dr. Ralph S. Paffenbarger Jr.

Identified the amounts and types of physical activity that were associated with improved health

Researchers started to quantify substantial health benefits of PA

Following the footsteps of Dr. Morris, Dr. Ralph S. Paffenbarger Jr. did studies on college alumni and longshoremen through which he was able to identify more precisely the amount and types of physical activities that are associated with improved health.


Physical Activity and Public Health-The Emergence of a Sub-Discipline

Eventually environmental health science began to explore the role of place and built environment on physical activity behavior.

With Epidemiology and exercise science in place, around 1990s behavioral sciences began to explore the behavioral determinants of physical activity and inactivity and started to investigate how inactive people could adopt healthier behaviors and this is how behavioral science became the part of physical activity and public health. Eventually environmental health science began to explore the role of place and built environment on physical activity behavior. Finally, a sub-discipline of physical activity and public health emerged as a combination of all the before mentioned field.


Role of PA in Chronic Disease Development

Chronic disease is the conditions and illness that occur over a long period of time. Due to the prolong nature, sometimes these diseases could be preventable or be delayed. For example ,type 2 diabetes which is responsible for one of the leading causes of death, has significant association with physical activity. Inactive adults have a higher risk for early death, heart disease, stroke, type 2 diabetes, depression, and some cancers. The map here is showing the percentage of adults who are in active in the US. Can you find out which states have the highest rates of inactivity? Can you find out the prevalence of chronic diseases in those states?


Ten Leading Causes of Death in the United States

Source: Xu, J., Kochanek, K. D., Murphy, S. L., & Tejada-Vera, B., Centers for Disease Control and Prevention, & National Center for Health Statistics. (2010). Deaths: Final data for 2007. National Vital Statistics Reports 58(19):1–21.

Almost 67% of the diseases that have identified as among the ten leading causes of death, are directly or indirectly related with physical inactivity.


From Science to Practice and Back


Ongoing, systematic collection, analysis, and interpretation of data essential to the planning, implementation, and evaluation of public health practice

Community interventions


Efficacy trials

Effectiveness studies

Development of Health Guidelines

Official policy statements usually developed by a government body, agency, or other reputable organization, that are based on the best available science.

Public health addresses three critical areas which are vital for improving health. These are surveillance, community interventions, and development of health guidelines.

Public health surveillance is ongoing, systematic collection, analysis, and interpretation of data essential to the planning, implementation, and evaluation of public health practice. Community interventions, the cornerstone of public health, are the collections of projects which are efficacy trials and effectiveness studies. Health guidelines are official policy statements, usually developed by a government body, agency or other reputable organization, that are based on best available science.


2008 Physical Activity Guidelines For Americans

Key Guidelines for Children and Adolescents (Aged 6-17)

Children and adolescents should do 60 minutes (1 hour) or more of physical activity daily.

Most of the 1 hour or more a day should be either moderate or vigorous intensity aerobic PA

Vigorous intensity should be at least 3 days/week

Muscle/bone strengthening activity should be at least 3 days/week

In 2008, the US department of health and human service published the first ever 2008physical activity guidelines for Americans. This document recommend the weekly amount of physical activity necessary for disease prevention and health promotion for children, adolescent, adult and older adults. In next couple of slides the key guidelines for PA for children, adolescent, adult and older adults have been listed.


Key Guidelines for Adults (Aged 18-64)

Adults should do 2 hours and 30 minutes or moderate intensity/week OR

1 hour and 15 minutes vigorous intensity aerobic/week OR

An equivalent combination of moderate and vigorous intensity aerobic PA.

Added health benefits:

If increased to 5 hours of moderate intensity/week OR

2 hours and 30 minutes of vigorous intensity PA/week OR

An equivalent combination

Should also add muscle strengthening activities 2 or more days/week

Key Guidelines for Older Adults

Older adults should follow the adult guidelines

Should be as physically active as their abilities allow

Important to avoid inactivity

Should do exercise that maintain or improve balance if they are at risk of falling

Promoting Physical Activity For Health

Social Ecological Model


Genetic make up, self-efficacy, sex, disability etc.


Peers, doctors, family members, organizations


Availability of trails, sidewalks, fitness facilities etc.


Educational policies, transportation policies etc.



Many researchers have used social ecological model as a guideline to explain multiple levels of PA. At the center if the target is the individual factors, factors that are innate for a person and differ among people such as age, sex, self –efficacy and so on. Moving out from the center, there is social influences that interact with PA. Determinants of social influences are the characteristics how a person interact with the society he or she lives in. Influences at this level could be peers, medical care organizations, family members and organizations like school, places or worship. The third level of influence we have in this model is environmental influences. These influences may encourage or restrict physical activity behavior of a person. For example, sidewalk, trails, fitness facilities, bicycle trails all are examples of environmental influences of PA. Finally the outer level of influence in PA is policy influences. These determinants are capable of making large change as they have potential to influence large amount of people. Examples of policy influences on PA is having educational policies in place, for instance mandating high quality physical education for school children.


Ecological Model of Childhood Obesity