Jane is a 32-year-old competitive athlete, homemaker and mother of two. She trains most weekdays, either running, cycling or swimming. Her family belongs to a club with recreation activities that they all enjoy regularly. Jane spends large parts of each weekday training and driving her kids to school and other activities. She never walks or bikes for pleasure, but prefers to drive. She enjoys curling up on the sofa to read or watch TV in the evenings and most weekends. Jane is fit and in good health, but is concerned about her family history of coronary heart disease. Her father died in his mid-thirties from heart disease and both of his siblings had bypass surgery.

At 55, Mei has a demanding career and four grown children. Two still live at home while they finish their education. Since Mei became a grandmother, she is rethinking the hours she spends at the office. She wants to make more time for her family. Mei never exercises, does not enjoy physical activity and tries hard to control her weight through diet. She has a BMI over 30 (see sidebar) and is afraid that she will develop the same Type 2 diabetes that her grandmother did. Mei has little energy in the evenings and can barely keep her eyes open through the evening news. She is not sleeping well and often thinks that she has too many work worries. A friend recently coaxed Mei into joining an early morning aqua-jogging class at the local recreation center. She hopes to keep up the weekly class.

All three women share similar education backgrounds, live in the same safe neighborhood and sent their children to the local school. They have easy access to a wide range of public and private sport and recreation facilities. Parks, a large trail system and good public transportation are close by. However, their physical activity is very different.

Why are these profiles important?

Mei, Carol and Jane’s stories illustrate the physical activity and health profiles of many women of the same age. They are concerned about chronic diseases such as diabetes and coronary heart disease, and conditions such as obesity. The many ways these women include or exclude physical activity in daily life is shown in their stories. The activities chosen and variety in how often they are done are fairly common in our population.

Carol, Jane and Mei are part of a group of adults that will eventually have more seniors living longer. This group will also have more problems with chronic disease.

The three women are at different points in the range of physical activity levels. This range is seen in the general adult population, where two-thirds of people are not active enough to achieve health benefits.
All three need to pay attention to their level of physical activity, especially since women on average are less active than men.
Along with other members of their families, these women play an important role in modelling behavior for their kids. Physical activity in youth can reduce the risk of chronic disease in adulthood.

Obesity

• Obesity increases the risk of developing conditions such as high blood pressure, Type 2 diabetes, heart disease, stroke, gallbladder disease and cancer of the colon, breast and prostate.

Body Mass Index

• Body mass index or BMI is a calculation used to determine whether a person is overweight. BMI is calculated by dividing body weight (in kilograms) by height (in meters) squared.
• A person with a BMI of 30 or more is considered obese, while a BMI score between 25 and 29.9 is considered overweight.
• Many factors impact a person's health risk relative to their BMI. Waist size, smoking, type of food eaten regularly, exercise, and medical conditions associated with obesity can all play a role.
• However, BMI numbers can be misleading for some, including those who are very muscular or women who are pregnant or breastfeeding.

Getting the most from physical activity

Significant health benefits can be gained by including a moderate amount of physical activity on most, if not all, days of the week. Examples include:

• 30 minutes of brisk walking
• 30 minutes of raking leaves
• 15 minutes of running
• 45 minutes of volleyball
Extra health benefits can be gained by doing more physical activity. People who maintain a regular routine of longer-lasting or vigorous activity are likely to have greater benefits.

- U.S. Surgeon General’s Report, U.S. Department of Health and Human Services, 1996.

Defining physical activity and chronic disease

Physical activity extends life, prevents disease and helps the body. It is body movement that uses energy, and includes a wide range of activities and intensities. The term ‘physical activity’ usually refers to arm and leg movements – in other words, the use of large muscles. Different types and amounts of physical activity are related to different health benefits. Exercise is a subset of physical activity. It generally refers to purposeful and planned activity. The aim of exercise is to reach a level of fitness. The activity is structured in a way that this level can be achieved.

Some facts:

In the U.S. more than 60 per cent of adults (aged 18 and over) are not active enough to achieve the best health benefits.
More women (67 per cent) than men (58 per cent) are inactive.
23 per cent of deaths in a year can be linked to physical inactivity.
Chronic diseases develop slowly, last for long periods of time, and often are never cured. Some cause few problems, surface occasionally and can be controlled with medication. However, chronic disease can also severely limit a person's ability to maintain routine activities like going to school, work, or taking care of basic needs.

Physical inactivity is a risk factor for many chronic diseases including heart disease, colon cancer and Type 2 diabetes. The causes of these chronic diseases are complex, but physical inactivity is one of the many risk factors. Most importantly, it is one risk factor that we can change simply by changing our behavior.

The link: physical activity and chronic disease prevention

If physical inactivity is a risk factor for chronic disease, does the reverse hold true? That is, if we are more active, will we enjoy better health? Yes! Regular physical activity can help protect you from many common deadly diseases. It improves health and increases your chance of preventing some chronic diseases. (See the table below for a summary of the research on positive effects of physical activity.)

How much activity is required to achieve health benefits?

Most people are not active enough to enjoy any health benefits. We need to do more, more often! It’s simple to learn how much activity you need. National and international guidelines recommend how much, how often and how intense physical activity needs to be to achieve health benefits.

If Mei and Carol increase their level of physical activity and Jane sustains hers, will they successfully protect themselves from chronic disease? It’s not a guarantee. Physical activity is only one risk factor for chronic disease. However, it is very important since it is one that we can change. By changing their behavior, Mei and Carol can benefit their health and reduce the risk of chronic disease. In increasing physical activity, they can show their kids an excellent example, feel better about themselves, improve sleep, reduce stress, and maybe even lose weight. If they keep it up, they will function better as they age.

Benefits of Physical Activity

HEALTH OUTCOME	ASSOCIATION
Longer life	Strong evidence of an increase
Coronary heart disease	Strong evidence of a decrease
Type 2 diabetes	Strong evidence of a decrease
Activities of daily living in the elderly	Moderate evidence of an increase
HDL (good) cholesterol	Moderate evidence of an increase
Blood pressure	Moderate evidence of a decrease
Body fat	Moderate evidence of a decrease
Colon (lower bowel) cancer	Moderate evidence of a decrease
Immune system functioning	Moderate evidence of an increase
Muskoskeletal injuries	Some evidence of an incrase

James F. Sallis and Neville Owen, 1998, Physical Activity and Behavioral Medicine, Thousand Oaks, California, Safe Publications.

Are there any risks?

Yes, there is some evidence that more musculoskeletal (muscle and skeleton) injuries are associated with being physically active. However, by increasing activity gradually and taking care not to over-exercise, injury can be reduced or avoided. Athletes like Jane, who are involved in frequent high-intensity training and events with a long duration, may be at greater risk. Still, the benefits of physical activity far outweigh the risks.

Challenges for Carol, Jane and Mei

Carol and Mei are a part of a group of women who need to be challenged to increase their level of activity. Jane also has some challenges. She must make sure she protects herself from overuse injuries. They can all benefit from following the health-related physical activity recommendations. Jane can also encourage and support women like Mei and Carol to engage in regular physical activity.

Knowing that a physically active life today can lead to improved health tomorrow gives us strong motivation to act now! Look beyond the stories of these three women to our entire population. It’s amazing to think about the scale of disease and death that can be prevented simply by getting more active! For more information about incorporating physical activity into your lifestyle, consult Canada’s Physical Activity Guide to Healthy Active Living or call 1-888-334-9769.

Chronic Disease Prevention The role of physical activity