This study investigated the effectiveness of an educational intervention, based on the transtheoretical model, for increasing employees’ physical activity. Stages of change in physical activity behavior in the intervention group, unlike the control group, improved significantly after three months of intervention. This result matches those of previous studies, which have reported that educational interventions based on the transtheoretical model can increase physical activity (
1,
9,
10,
18-
23). However, Hutchison et al. studied the interventions based on the transtheoretical model for changing physical activity behavior and showed that the model may not be the most appropriate for changing physical activity behavior. They argued that most of previous studies had not considered all the aspects of transtheoretical model and concluded that the effectiveness of this model cannot be judged until the interventions applied it properly (
24).
Our comparison of the stages of behavior change three and six months after the intervention revealed that a number of individuals returned to past stages in the process of behavior change. For instance, some individuals in the action stage returned to the contemplation stage. This possibly because the individuals did not experience the expected benefits (such as weight loss) of physical activity, which could have led to a reduction in their perceived benefits of physical activity. This result highlights that to improve physical activity behavior, more attention should be paid to individuals who are in the action stage. Further, investigations should be carried out to identify the reasons for regressing from an advanced stage to a past one, to better design interventions.
In this study, the least number of return to a previous stage were seen among individuals in the maintenance stage. This is in agreement with the findings of Prochaska et al., who showed although individuals may return to an earlier stage at any point in the behavior change process, it is less likely among individuals in the maintenance stage (
25). Therefore, to be successful, educational interventions should promote behavior that helps individuals attain the maintenance stage.
Results of the repeated measure analysis showed that in the intervention group the mean scores of perceived benefits of exercise were significantly different before and three and six month after the intervention (
Tables 6 and
7). Three months after the intervention perceived benefits scores had significantly increased, which is in agreement with the results of some studies (
1,
18,
20). However, the mean score of perceived benefits declined slightly six months after the intervention, possibly because the participants may have forgotten the educational material over the time. This finding highlights the need for continuous education until individuals fully comprehend the benefits of exercise. Some of the common perceived benefits that employees cited in group discussions included a feeling of freshness, better sleep at night, less pain in the lower back, neck, and feet, fitness, and prevention of cardiovascular diseases. In a study on obese women, the perceived benefits of physical activity were reported to be a sense of achievement and success, increased energy, stress relief, and physical fitness after delivery (
10).
As with the control group, in the intervention group, perceived barriers did not decrease after the intervention although other studies have shown that an educational intervention based on transtheoretical model can decrease the perceived barriers significantly (
1,
18,
20,
21). The lack of decrease in perceived barriers can be attributed to the fact that some barriers could not be remedied by the educational intervention. For example barriers like remotely located exercise places and lack of encouragement by friends and family members cannot be removed through an educational intervention among the participants. Other solutions to reduce such barriers should be considered. Some solutions may include communication with relevant agencies such as the Ministry of Youth and Sports and the municipalities to increase public access to sporting facilities and installing sport equipment in all the parks. Further, barriers like “not having free time to exercise” could not be addressed through our educational intervention, and other solutions such as encouraging managers to allocate some place and time for employees’ physical activity in the offices should be considered.
Individuals who were in the preparation stage and did not enter the action stage despite the educational intervention cited not having free time, being away from sport places, warm weather, and long working hours as the greatest barriers to physical activity. Similar factors have been identified by studies. In a study by Tavakoli et al., the main perceived barrier for physical activity was reported to be not having free time for physical activity (
26). Fahrenwald and Walker found that some of the perceived barriers to exercising were getting tired after exercise, cold weather, and child care (
10). Aghamolaei et al. showed that the barriers to exercise among students are shortage of time and feeling tired after the exercise. They also found that factors like self-efficacy and support from friends encourage students to engage in physical activity (
3). One of barriers which for the older participants was that sport clubs lack specific arrangements for old people to exercise. This is an interesting insight, and we believe that governments should plan to develop sport teams and clubs for older people to encourage physical activity.
Some strategies proposed by participants of this study to reduce physical activity barriers included increasing access to sports facilities, training one of the employees to be a fitness trainer, holding sports classes at work, setting up a swimming pool and hiking group, and biking to work instead of using vehicles. According to Tavakoli et al., the most important measures to increase physical activity are facilitating access to exercise facilities, making exercise opportunities available in offices, and holding fitness classes at work (
26).
Our results showed a significant difference in the mean scores of self-efficacy before and three and six months after the educational intervention in the intervention group while no such difference was observed in the control group (
Tables 6 and
7). This finding is consistent with those of Moeini et al. (
1), Hashemi et al. (
18), Moradi et al. (
20), and Dallow and Anderson (
9). However, it is inconsistent with the results reported on Si et al. in their study on deaf youth (
21).
A remarkable finding of this study is that unlike the scores of perceived benefits and stages of behavior change which decreased over the time, the self-efficacy score not only decreased but also increased slightly between three and six months after the intervention. This finding emphasizes that if self-efficacy can be increased through educational intervention, one’s self-confidence for physical activity will probably improve, which can ensure longer compliance even if the educational intervention is not repeated. In addition, self-efficacy can indirectly boost physical activity by reducing the perceived barriers (
18). Mazloomy et al. also showed that self-efficacy has an important role in increasing physical activity (
27). Therefore, in educational interventions particular attention must be paid for strengthening this cognitive factor (
28).
During the educational intervention, group discussions aiming to increase participants’ awareness of physical activity benefits and the risks of inactivity were welcomed by participants, especially when the sessions were held during working hours. The posters on exercise at work were also greatly appreciated. Educational CDs (including instructions on swimming, aerobics, women’s bodybuilding, fitness using balls, skating, and yoga) did not get much attention from individuals who were in the preparation, action, and maintenance stages. A notable point about the educational CDs was that individuals in the precontemplation and contemplation stages had not viewed the CDs even several weeks after they received them. This indicates that educational materials aimed at helping people learn on their own are not appropriate for those who are in precontemplation and contemplation stages. To ensure that individuals benefit from educational CDs and videos, the content should be aired during sessions and classes.
The results of this study show that educational interventions based on the transtheoretical model can improve stages of change of physical activity behavior and cognitive factors such as perceived benefits and self-efficacy for exercise up to three months after the intervention, but over the time (six months), the changes may decrease. This learnings from this study can be used for improvement of physical activity behavior. Efforts should be made to continue with the educational intervention until all the participants enter the maintenance stage.