Reading Links: Introduction

Why Exercise Matters

Before you can move forward in this class, it’s important that you understand the basic definitions of physical activity and exercise. In addition to learning some vocabulary, it is also helpful to know about common barriers to physical activity and how to overcome them.

Physical activity literacy begins with a clear understanding of the terminology utilized within the field. While some terms are used interchangeably, it is important to recognize the nuanced differences which exist in physical activity vocabulary.

Physical Activity: Any bodily movement that is produced by skeletal muscles and requires energy expenditure (calories “burned”). Physical activity is often divided into four domains: Domestic/household, transportation, occupational, and leisure-time [1].

Examples of the various domains of physical activity are as follows:

  • Domestic/household: vacuuming, completing yardwork, clearing the dishes
  • Transportation: biking to work, walking to school, rollerblading to the store
  • Occupational: lifting or hauling weights for work or engaging in exerting physical activity during a work-related task
  • Leisure-time: physical activity which is completed in an individual’s leisure-time (i.e., swimming, jogging, hiking, dancing, participating in weight-training regimens, etc.

ADL: ADLs are activities of daily living, which often involve physical activity. ADLs may often be interchanged with the term “lifestyle activities.” Some examples of ADL’s include: gardening, doing dishes, mowing the lawn, or walking to school.

Exercise: A subcategory of physical activity that is planned and structured. Exercise involves repetitive bodily movement, and is performed with the goal to improve or maintain one or more components of physical fitness [2].

Two broad categories of exercise include aerobic and anaerobic exercise.

Aerobic Exercise (Oxygen is utilized in the energy-generating process for muscle contraction):

Exercise which:

  1. primarily uses the large muscle groups of the body
  2. is typically performed continuously
  3. can be maintained for a longer duration of time than anaerobic exercise
  4. improves cardiorespiratory endurance (Physical Activity Guidelines Advisory Committee, 2008).

Several examples of aerobic exercise include jogging, rowing, and biking.

Anaerobic Exercise (Oxygen is not utilized in the energy-generating process for muscle contraction): Exercise which uses muscles at high-intensity for shorter bursts of time (Physical Activity Guidelines Advisory Committee, 2008).

Flexibility Exercise: Exercise which is designed to improve full range of motion of the body’s joints (Physical Activity Guidelines Advisory Committee, 2008).

Physical Fitness: A specific set of attributes possessed by an individual, which allows her/him to perform physical activity with ease, and in the absence of undue fatigue. Physical fitness includes the following components:

  • Cardiorespiratory Endurance (aerobic fitness)
  • Skeletal Muscle Endurance
  • Strength
  • Power
  • Flexibility
  • Balance
  • Movement Speed
  • Reactionary Time
  • Body Composition [3]

Physical Inactivity: A lack of physical activity; not meeting specific physical activity guidelines [4]

two people lifting weights in a workout class

Suggestions for Overcoming Physical Activity Barriers

Lack of time

  • Identify available time slots. Monitor your daily activities for one week. Identify at least five 30-minute time slots you could use for physical activity.
  • Add physical activity to your daily routine. For example, walk or ride your bike to work or shopping, organize school activities around physical activity, walk the dog, take the stairs, exercise while you watch TV, park farther away from your destination, etc.
  • Select activities, such as walking, jogging, or stair climbing that you can do based on the time that you have available (e.g., 5 minutes, 10 minutes, 20 minutes).
  • Take advantage of work physical activity facilities and/or programs. Hold walking meetings and conference calls if possible. During phone calls try to stand, stretch, or move and walk around some, if possible.

Social support

  • Explain your interest in physical activity to friends and family. Ask them to support your efforts.
  • Invite friends and family members to exercise with you. Plan social activities involving exercise.
  • Develop new friendships with physically active people. Join a gym or group, such as the YMCA or a hiking club.

Lack of energy

  • Schedule physical activity for times in the day or week when you feel energetic.
  • Convince yourself that if you give it a chance, physical activity will increase your energy level; then, try it.

Lack of motivation

  • Plan ahead. Make physical activity a regular part of your daily or weekly schedule and write it on your calendar.
  • Invite a friend to exercise with you on a regular basis and write it on both your calendars.
  • Join an exercise group or class.

Fear of injury

  • Learn how to warm up and cool down to prevent injury.
  • Learn how to exercise appropriately considering your age, fitness level, skill level, and health status.
  • Choose activities involving minimum risk.

Lack of skill

  • Select activities that don’t require new skills, such as walking, climbing stairs, or jogging.
  • Take a class to develop new skills.

High costs and lack of facilities

  • Select activities that require minimal facilities or equipment, such as walking, jogging, jumping rope, or calisthenics.
  • Identify inexpensive, convenient resources available in your community (community education programs, park and recreation programs, worksite programs, etc.).

Weather conditions

  • Develop a set of regular activities that are always available regardless of weather (indoor cycling, aerobic dance, indoor swimming, calisthenics, stair climbing, rope skipping, mall walking, dancing, etc.)

In this course, we’ll learn more about how to apply to these terms to your own life. You may also want to check your local library’s website for more research on these topics.


  1. Caspersen, Powell, & Christenson, 1985; Physical Activity Guidelines Advisory Committee, 2008
  2. Caspersen, Powell, & Christenson, 1985; Centers for Disease Control and Prevention, 2015
  3. Caspersen, Powell, & Christenson, 1985; Centers for Disease Control, 2015
  4. Caspersen, Powell, & Christenson, 1985; Sedentary Behaviour Research Network, 2017