Unintentional（无意识的） physical activity may be influenced by non-conscious attitudes, noted¹ David Conroy, associate professor of kinesiology（运动机能学，人体运动学） and human development and family studies. The challenge of encouraging more activity can be met by understanding the motivation behind both deliberate（故意的，从容的） exercise and inherent（固有的，内在的） behaviors. "If you aren't in the habit of being physically² active, you can run out of energy trying to force yourself to do it everyday," said Conroy. "But if you can make physical activity habitual³, being active becomes a lot easier."

Efforts to increase physical activity are at the forefront（最前线） of public health research because the benefits of a healthy lifestyle go far beyond physical and mental well-being⁴. However, the majority of these efforts focus on explicit⁵（清楚的，明确的） motivation -- external factors that lead to a change in behavior. Explicit motivation can include following the U.S. Department of Health and Human Services' recommendation for 150 minutes of aerobic⁶（需氧的） activity throughout the week, or making plans with a friend to start a weight-loss program.

But explicit motivational processes are often unsuccessful in causing changes that people can easily maintain long-term.

Conroy, along with Shawna Doerksen, assistant professor of recreation, park and tourism management; Amanda Hyde, graduate student in kinesiology; and Nuno Ribeiro, graduate in recreation, park and tourism management, examined 200 college students for a connection between physical activity and level of unintentional activity.

"It wasn't the overall level of activity we focused on, it was specifically the unintentional activity -- those little things that you don't even think about that help you burn those extra few calories," said Conroy.

Their results, published in the April issue of Annals of Behavioral Medicine, show a positive correlation⁷（正相关） between individuals who have a positive attitude about physical activity and those who performed more unintentional physical activity, such as climbing stairs instead of waiting for the elevator, or walking further to the store because of parking in the first available spot rather than searching for a closer space.

The researchers measured the students' unexpressed attitudes towards exercise with a common psychological test that uses words or pictures to trigger a person's automatic response. The computer-based test requires categorization（分门别类） of a stimulus⁸, in this case a type of physical activity, with words that are either "good" or "bad." The faster a person associates a pairing as either good or bad, the more strongly they connect those two things in their memory.

Conroy and Doerksen also used questionnaires（问卷，调查表） to determine the amount of physical activity the students predicted they would get during the week. The amount varied⁹, depending on how active students were in their social group or the outcomes they expected from physical activity.

The researchers fit each student with a pedometer（步程计） to calculate the total activity he or she experienced during one week. The amount of unintentional activity is estimated by adjusting total activity scores to account for people's intentions to be active.

"We're trying to follow this up now by looking at a broader range of populations," said Conroy. There are major differences in what motivates young adults, mid-life adults or parents, and older adults who may have physical limitations, he noted.

The researchers are now exploring whether there are ways to promote or encourage physical activity without a person knowing it.