Chapter 27: Living with and beyond cancer
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Definition
Physical activity is defined as any bodily movement produced by the skeletal muscles that results in a substantial increase in energy expenditure (Bouchard et al. [24]). It is important to recognize that all activities involving movement during our daily life such as housework or walking to work are forms of physical activity.
In contrast, exercise is a specific form of physical activity where the goal is to achieve some increase in fitness. It is usually carried out in a more purposeful fashion and at a more intense level and over an extended period of time (Courneya and Friedenreich [249]). The terms physical activity and exercise are often used interchangeably but, whichever term is used, the intensity of the activity is important when considering the extent of physiological changes.
Definition of exercise levels
There are many tools to help gauge the intensity of exercise and physical activity, but one that is commonly used for people with cancer is the Borg scale, which rates the perceived level of breathlessness on exertion (Borg [23]). A modified Borg scale (Figure 27.31) uses numbers 0 to 10, with 10 being maximal exertion.
Figure 27.31 Modified Borg scale of perceived exertion. Source: https://www.cdc.gov/physicalactivity/basics/measuring/exertion.htm.
Moderate intensity aerobic exercise (5–6 on the modified Borg scale) is at an intensity that raises the heart rate but it is possible to still talk.
Vigorous intensity aerobic exercise (about 9 on the modified Borg scale) is at a level where the heart rate is significantly increased, which makes it difficult to speak more than a few words without pausing for breath.
