There are many ways adults can increase their participation in PA
. The goal of this pilot study was to examine feasibility and short-term efficacy of a PA program that targeted changing a traditionally sedentary leisure-time behavior (TV viewing) into an active one. The results suggest that a small behavior change, like stepping in place during TV commercials, was both effective and acceptable to adults. At baseline, no participants were meeting the guidelines for aerobic activity (≥150 min/wk). TV Commercial Stepping and Walking both resulted in about 70% of the previously inactive participants meeting the volume requirements of the 2008 PA guidelines, but only the walking group accumulated their PA in continuous bouts of 10 minutes or more. Despite the different approaches to increasing PA, the volume of exercise for both groups was approximately equal. Stepping in place during commercials for least 90 min/d of TV viewing resulted in an increase in daily steps (~3000) roughly equivalent to that which occurred as a result of instructing participants to walk at least 30 min/d (a traditional PA recommendation). Participants in both groups moved from what is considered “sedentary” (<5000 steps/d) to “somewhat active” (7500–9999 steps/d) categories
. This novel strategy of TV Commercial Stepping can incorporate exercise into one’s lifestyle, and it has the additional benefit of breaking up sedentary time. Recent evidence suggests that there are health benefits (e.g., a reduction in cardiovascular risk factors) associated with interrupting prolonged periods of sedentary activity with short bouts of standing and physical activity
[15, 18], and it is of interest that Healy et al. and Dunstan et al.
[18, 26] have reported that the associations between health and breaking up sedentary time are independent of total sedentary time and moderate-to-vigorous intensity activity. Alternatively, combining TV Commercial Stepping with a traditional exercise program as a way to “boost” overall activity levels may be of interest. As well as boosting overall activity levels, combining TV Commercial Stepping with a traditional exercise program would have the benefit of addressing both prolonged sedentary periods and activity. As these both have independent associations with health this may be a particularly effective ‘two pronged’ approach.
The high rate of attendance to behavioral-based sessions, and high percentage of participants reporting that they planned to continue their current PA practices reflects the high acceptability for both PA interventions. The TV Commercial Stepping intervention was equally acceptable as the Walking intervention. Time and motivation to be physically active continue to be barriers that prevent people from PA compliance. Compliance can be enhanced by home-based exercise programs, and using short bouts rather than long bouts of activity for individuals who “can’t find the time to exercise”
[27–30]. TV Commercial Stepping requires no additional time (if worked into the TV programming already being watched), it involves minimal equipment, and can be performed in the comfort of an individual’s home. As an alternative, participants could be encouraged to be physically active (i.e., walk on the treadmill, use the elliptical trainer, stepping in place) throughout the entire 30-min program. However, there was no attempt to test that approach in the current investigation.
An unanticipated outcome of this study was the reduction in TV viewing seen in both groups (Figure
2, and Table
2). Significant evidence demonstrates that TV viewing and PA are inversely related
[31–33]. It is possible that TV viewing time was reduced in the Walking group because it was replaced by the 30-min walks, and it may have been reduced in the TV Commercial Stepping group because they associated it with PA. Other possibilities are that the self-monitoring, and subsequent awareness of TV viewing impacted their habits, or there could have been seasonal variation. While it is hypothesized that TV viewing and PA are substitute behaviors, eating and TV viewing appear to be complementary behaviors
. An interesting outcome of this study is that both groups reported a reduction of TV-related energy intake and total daily energy intake. However, with only 3 days of dietary data at baseline, 3, and 6 mo, it cannot be determined how participants ate throughout the entire 6-mo period. Also, because dietary intake was self-reported, participants may have under reported energy intake.
Participants maintained their body weight over 6 months, although they had small decreases in adiposity (body fat percentage and circumference measures). These small anthropometric changes are consistent with other short-term (<12 months) exercise-only programs that have resulted in minimal or no changes in weight
. The 2008 Physical Activity Guidelines recommend ≥ 150 min/week for overall health, but 150–300 min/week for weight loss
. Thus, it is not surprising that the present study, in which participants performed about 150 min per week of moderate PA, resulted in small decreases in percent body fat, but no loss in body weight. Even in the absence of weight loss, increasing PA can result in positive health outcomes
[12, 36, 37]. For this reason, interventions are beneficial if daily step counts increase, independent of whether or not participants achieve weight loss
There are several limitations of the present study. This pilot study is limited by its small sample size, disproportionate female gender participation, and limited ethnic diversity. To better generalize the findings of this study, future work will focus on the recruitment of minorities and men. The approach of using TV Commercial Stepping to accumulate PA does have weaknesses; it requires the individual to watch TV, a sedentary behavior. On days when participants did not watch any TV, they were unable to meet their PA goals through this strategy. In the current study design, participants were followed for 6 months, with no follow up after that time point. While we learned that it is possible to intervene during an adult’s TV time, it would have been useful to include a self-report measure of domain-specific sedentary behaviors to systematically assess a wide range of sedentary behaviors. Lastly, there is a need to establish the sustainability of TV Commercial Stepping. Many of the strengths of this innovative study have been highlighted throughout the discussion. The combination of self-report and objectively measured PA is a noteworthy strength. At slower walking speeds some pedometers have been shown to be less accurate. If a participant was stepping in place, walking around the house, or walking outside at a slow walking speed there is the potential that step counts were underestimated. To prevent this from being a major concern, all participants were instructed to “briskly” step in place, or “briskly” walk continuously for the duration their activity bouts. Also, during the first 3 monthly treatment meetings participants demonstrated proper stepping/walking pace. The Omron HJ-303 pedometer used in this study has been shown to provide a valid estimation of steps for walking speeds ranging from 2–8 mph
. This study addresses a gap in the literature by testing a potential new strategy in the effort to increase the PA levels and break up sedentary time in the population. It is now evident that stepping during each commercial break is achievable, and it may be worth exploring whether participants might prefer at times to walk in place for the length of a 30-minute program instead of more frequently over the course of a couple of hours. At this early stage of intervention development, the observed outcomes highlight many intriguing issues worthy of future exploration. Without a control group, that received no intervention, it was not possible to determine if either treatment prevented weight gain.