Introduction
Physical inactivity is a growing problem in the USA, especially for older people and for those with chronic diseases, such as chronic obstructive pulmonary disease (COPD). Sixty-three percent of older adults do not meet the 2008 Physical Activity Guidelines for Americans, and the problem is even greater for people with COPD. A recent systematic review reported that the duration (57%) and intensity (75%) of physical activity (PA) was lower for people with COPD than for age-matched healthy individuals. In another systematic review, it was noted that people with COPD took fewer steps/day than people with most other chronic diseases; in fact, people with COPD were among the least active groups.