self-monitor their daily steps. Participants logged their goals and daily step counts to monitor their progress. Coaching sessions were dedicated to different behavioral strategies each week. In week 1, participants learned about step counting basics and goal setting using the SMART (specific, measureable, attainable, realistic, time-limited) system. In week 2, participants discuss barriers to activity and the challenges of making trade-offs focusing on the benefits of physical activity and the sacrifices that may come with achieving their goal. During week 3, participants set new goals and work to brainstorm strategies that can help them achieve their step goal. In week 4, participants refine their goals and talk about relapse prevention. The intervention was targeted to the partic- ipant population by including discussion of the role of physical activity in colon cancer etiology. The SDCC 10,000 step goal is readily achievable for individuals who are attaining already 6–8,000 steps/day in their usual daily activity and are adding 30 (2–3,000 steps) minutes of additional purposeful walking. However, data in chronically diseased and sedentary populations indicates daily step counts are likely to be much lower (3–5,000 steps/day) [26]. For those individuals whose baseline step count is lower and in the higher dose arm, the coach worked to progress them to a safe and reasonable goal driven by the time goal (30 vs 60 minutes/da of walking) and using their pedometer recorded step counts as a motivational and self- monitoring tool. To maintain attendance rates, participants who missed a session received follow-up calls and reminders for future sessions. In phase two, participants received eight weeks of brief phone support. Participants walked on their own, monitoring progress using pedometers. Participants were contacted by phone and asked to report their pedometer wear time, last daily step count and were given the opportunity to ask questions or get additional feedback as needed from the coordinator. Measures Data collection was completed at Washington University School of Medicine. Baseline measures were taken prior to the initiation of the intervention and follow-up measures following the last week of intervention. To measure the outcome of step count change, independent of self-monitoring, participants wore a sealed blinded pedometer for one week at baseline and at follow-up and logged their wear time. Participants had to report wearing the pedometer for at least eight hours/day to be considered a valid day of wear. Only valid wear days were included and the average steps/day during the week was based only on days worn. We used the Omron HJ 720 IT pedometer (Omron HealthCare, IL), which has been shown to have higher validity in overweight and obese individuals. Wear time was estimated based on the hourly counts provided by the device output, which records counts per hour. Participants also wore an Actigraph GT1M (Actigraph, Pensacola, FL) accelerometer for one week at baseline and at follow up to measure moderate/vigorous physical activity as an additional outcome. The accelerometer had to be worn a minimum of 10 hours to be considered a valid day. Data was collected in 60 second epochs. Data was processed using the ActiLife software (Actigraph, Pensacola, FL) and the Freedson equation was used to define activity intensity cutpoints and time in moderate/vigorous physical activity. All study participants received $50 each for completing the baseline and follow-up assessments. Participants were also given an unblinded pedometer at the study conclusion. Analysis To be conservative in estimating the intervention effect, in all analyses, participants who recorded baseline data, but did not Physical Activity in Patients with Colon Adenomas record follow-up data were included in the analyses; with the baseline value carried forward as no change. Fisher’s exact tests were used to compare demographics between the two study arms because of small numbers in some cells. Paired t-tests were used to examine change from baseline to follow-up. T-tests were used to compare the intervention arms using an intent-to-treat analysis. Results Recruitment began in June 2009 and enrollment was completed in December 2009. 265 of the 399 (66%) individuals sent an invitation letter were reached and screened via telephone. 101 did not meet inclusion criteria (38%) and 136 declined participation (51%). 28 qualified for the intervention, and 17 consented and enrolled. 16 were randomly assigned to one of two arms. One participant was unable to commit to study requirements after completing consent and baseline measures and was not random- ized. 13 of the 16 enrolled (81%) completed the intervention (five in the standard dose arm and eight in the high dose arm) and12 (75%) completed the accelerometer protocol (Consort Diagram S1). The most common reasons for not qualifying were age, disabled/unable to walk, and already exercising regularly. Of the 3 who did not complete the intervention, 1 was unable to commit to the study requirements and 2 were lost to follow up. Of the 16 participants, 12 recorded 5 or more days of valid accelerometer wear time, and 4 failed to meet the accelerometer wear time requirements at baseline. Of the 13 participants who completed the intervention, 12 recorded 5 or more days of valid accelerom- eter wear time one recorded 4 days. Pedometer wear time was similar, with 11 participants recording at least 5 days of valid wear time, 2 participants recording 4 days, 2 participants had 3 days and 1 had 2 days of valid wear time. At follow-up, 11 of the 13 participants recorded 5 or more valid days of pedometer wear time, with the remaining 2 recording 1 day and 3 days, respectively. The population ranged in age from 45–66. 63% (n = 10) of the participants were African American (Table S1) and most (81%) were female. The participants were largely employed (63%) and most had some post-high school education. There were no significant differences between the two intervention arms on any sociodemographic factors. Participants recorded steps typical of chronically diseased adults, with a mean of 4549 (standard deviation(sd) 2720) steps/ day at baseline (Table S2). Participants were also insufficiently physically active as measured by accelerometer, recording 96 (sd 106) minutes/week of moderate/vigorous intensity physical activity. The intervention significantly increased mean physical activity levels, measured by blinded pedometer (1791 (sd 2065) steps/day) and accelerometer (105 (sd117) minutes moderate/ vigorous intensity physical activity/week). Participants in the standard dose arm increased moderate/vigorous activity by 65 (sd130) minutes/week and increased steps by 836 (sd 1284) per day. In the high dose arm, participants increased steps by 2746 (sd 2325) per day and moderate/vigorous physical activity by 133 (sd107) minutes/week. Both arms failed to reach the intervention daily step target, recording an average of 6340 (sd 3363) steps/day at follow-up. However, this was a significant change from baseline (p = 0.003). Despite not meeting the step count target at follow-up, participants in both arms met the time-based exercise prescription, recording a mean of over 200 minutes/week of moderate/ vigorous physical activity and qualifying them as meeting the US Physical Activity Guidelines. This was also a significant increase over baseline (p = 0.01). PLoS ONE | www.plosone.org 3 July 2012 | Volume 7 | Issue 7 | e39719