Recommendation 3 Background
To understand PAL or physical activity level of 1.75, it is helpful to know what basal metabolic rate means. Basal metabolic rate is the amount of calories per hour required to maintain essential body functions (breathing, heart beating, etc.) during resting and fasting conditions.
If you take the basal metabolic rate as 1, the remainder or 0.75 represents the work of the body to move, walk, sit, stand, run, and so on. People who are relatively sedentary are likely to be at a physical activity level or PAL of 1.55 to 1.60. Individuals with an occupation that involves regular physical activity are likely at a physical activity level (PAL) of 1.75 or greater.
An extra hour of moderate physical activity a day plus an hour of vigorous activity a week can raise the PAL from 1.55 or 1.6 to 1.75 or more.
The panel feels that there is convincing evidence that regular physical activity protects against colon cancer. Also, regular physical activity possibly protects against cancer of the breast and lung.
An added benefit of physical activity comes from its protection against overweight and obesity. Obesity puts a person at a greater risk of some forms of cancer. See Recommendation 2.
See "How to" for practical information
BACK TO FOURTEEN RECOMMENDATIONS
Prepared 1998 by Bernadene Magnuson, Ph.D.
University of Idaho, Dept. of Food Science and Toxicology - EXTOXNET FAQ Team.