Psychological Determinants of Physical Activity in Japanese Female Employees

Transcription

1 J Occup Health 2003; 45: Journal of Occupational Health Psychological Determinants of Physical Activity in Japanese Female Employees Yuko NISHIDA 1, Hisao SUZUKI 2, Da-Hong WANG 1 and Shohei KIRA 1 1 Department of Public Health, Okayama University Graduate School of Medicine and Dentistry and 2 Faculty of Education, Okayama University, Japan Abstract: Psychological Determinants of Physical Activity in Japanese Female Employees: Yuko NISHIDA, et al. Department of Public Health, Okayama University Graduate School of Medicine and Dentistry To understand how psychological characteristics influence adoption and maintenance of physical activity/exercise, we conducted a crosssectional study among Japanese employees based upon the idea of stages of behavior modification. The study population consisted of 719 employees (male, 396, female, 323) from five medium-sized manufacturing companies ( employees) in Okayama Prefecture, Japan. The female response rate was 67.5% (n=218), among which 201 eligible female subjects (62.2%) were analyzed. The study questionnaire included demographic characteristics, physical activity/exercise measures, self-efficacy measures, and perceived benefit and barriers scales. Participants were asked to select the items that best described their current physical activity/exercise level from an 8-item questionnaire, and we converted their answers to the 5 stages of change according to a transtheoretical model of behavior change. Perceived benefit and barrier scales were classified into 7 factors (4 benefits and 3 barriers) by factor analyses. The relationship between psychological determinants and the stage of physical activity/exercise was examined by one-way analysis of variance. Only 10% of the subjects had moderate physical activity (in the action and maintenance stages) regularly. We found that selfefficacy, weight control benefit, physical barrier and time barrier were psychological determinants of physical activity/exercise stages in female employees, and especially there was a consistent relationship between self-efficacy and the stage of physical activity/ exercise. Our data suggest that health education for Japanese female employees requires that health Received May 23, 2002; Accepted Sep 5, 2002 Correspondence to: Y. Nishida, Department of Public Health, Okayama University Graduate School of Medicine and Dentistry, Shikata-cho, Okayama City, , Japan professionals should provide support for strengthening self-efficacy, show practical ways to increase physical activity in daily life, and provide broad and accurate information showing that physical activity/exercise have a good effect on health. (J Occup Health 2003; 45: 15 22) Key words: Physical activity, Transtheoretical model, Japanese female employees, Self-efficacy, Weight control benefit, Physical barrier Regular exercise is reported to be very important for psychological and physical health 1) but in modern society more and more people tend to slip into sedentary behavior in their daily life. In Japan, the proportion of individuals who do regular exercise is only 30.2% and 27.5% among men and women, respectively 2), particularly low among women between the 20s and 40s. The National Health Promotion Movement in the 21st Century has recommended that each individual should increase physical activities in daily life to prevent disease and increase quality of life, and the proportion of Japanese population doing regular exercise should be increased to 39% and 35% among men and women, respectively, by But how to reach these goals is not indicated. Recently, not only regular exercise but also regular physical activities have been regarded as important for a healthy lifestyle. In the report by Casperson et al. 3), physical activity has been defined as any bodily movement produced by skeletal muscles that results in energy expenditure, and closely related to, but distinct from, exercise, but exercise is a subset of physical activity defined as planned, structured and repetitive bodily movement done to improve or maintain one or more components of physical fitness. In Europe and the United States, understanding the reason why people choose to be physically inactive has been discussed based on the models of behavioral science. One of the most effective models is the transtheoretical model of behavior change (TTM). It was developed by

2 16 J Occup Health, Vol. 45, 2003 Prochaska and DiClemente as a general model of intentional behavior change 4). TTM was originally developed for application in the area of smoking cessation, and this model was also applied to a smoking cessation program in workplaces in Japan 5). Recently it has been extended to research on many forms of health behavior including exercise in Europe and the United States 6). TTM postulates that individuals engaging in a new form of behavior move through the following five stages: (1) Precontemplation (PC)- subjects express lack of interest in making change; (2) Contemplation (C)- subjects are thinking about making a desired change; (3) Preparation (PR)- subjects are doing some physical activity but not meeting the recommended criteria; (4) Action (A)- subjects are meeting the above-mentioned (preparation) criteria on a consistent basis but they have not maintained the behavior for 6 months, and (5) Maintenance (M)- subjects have been in action for 6 months or more 6, 7). Physical activity and exercise are influenced by a variety of psychological, social and environmental variables, some of which are associated with physical activity and exercise and are modifiable, including selfefficacy, social supports, perceived benefit, perceived barriers and enjoyment 1, 8), and these variables are considered to be determinants of the individual s stage of physical activity and exercise. But few studies in Japan have examined the relationship between these determinants and the stage of physical activity/exercise. The present study attempted to examine how forms of behavior relate to physical activity/exercise together with the psychological influence in order to elucidate what are psychological determinants of the stage of physical activity/exercise in Japanese female employees, and further to develop effective physical activity/exercise interventions for risk reduction in lifestyle-related disorders in worksite-based settings. Subjects and Methods The study was carried out from April to September The study population consisted of 719 employees (male, 396 and female, 323) from five medium-sized manufacturing companies ( employees) in Okayama Prefecture, Japan. All subjects were asked to complete a self-administered questionnaire, including information on age, occupational status, education level, working time per day, level of physical activity 9), the usual patterns of physical activity/exercise, and psychological characteristics as well. The authors confirmed all completed questionnaires. The response rate was 73.2 % (n=526), among which 67.5% were female subjects (n=218). After exclusion of 17 subjects with incomplete questionnaires, 201 eligible female participants (62.2%) remained for data analysis. The reason we analyzed only the female subjects was that several studies have indicated clear gender differences in psychological determinants concerning exercise 10, 11). All subjects were apprised of the purpose of the study and signed to informed consent. Table 1. Proportion of the study population at each physical activity/exercise level and stage Level n (%) Transtheoretical model n (%) 1. I do not exercise or walk regularly now, and 46 (22.9) 1. Precontemplation 46 (22.9) do not intend to start in the near future. 2. I do not exercise or walk regularly, but I 78 (38.8) 2. Contemplation 78 (38.8) have been thinking of starting. 3. I am trying to start to exercise or walk, or I 48 (23.9) exercise or walking infrequently. 3. Preparation 58 (28.9) 4. I am doing vigorous exercise less than 3 times per week 10 (5.0) or moderate physical activity less than 5 times per week. 5. I have been doing moderate physical activity 5 or more 7 (3.5) times per week (or more than 2 1/2 hours per week) for 4. Action 7 (3.5) the last 1 6 months. 7. I have been doing vigorous exercise 3 to 5 times per 0 (0) week for 1 6 months. 6. I have been doing moderate physical activity 5 or more 12 (6.0) times per week (or more than 2 1/2 hours per week) for 5. Maintenance 12 (6.0) 7 months or more. 8. I have been doing vigorous exercise 3 to 5 times per 0 (0) week for 7 or more months.

3 Yuko NISHIDA, et al.: Psychological Determinants of Physical Activity 17 The study was approved by the Ethical Committee of Okayama University Graduate school of Medicine and Dentistry. Physical activity and exercise measures To measure physical activity and the exercise level, we used a questionnaire developed by Martin et al. 12), in which regular physical activity (in the action and maintenance stages) is doing moderate physical activity such as walking, gardening and cycling 5 times or more per week to prevent disease and increase quality of life (the Center for Disease Control and Prevention and the American College of Sports Medicine guidelines for health benefit 13) ), and regular exercise is doing vigorous exercise such as basketball, tennis, running and the like 3 to 5 times per week (the American College of Sports Medicine recommendations 14) ). In the present study, the participants were asked to select the items that best described their current physical activity/exercise level from an 8-item questionnaire, and we converted their answers to the 5 stages of change according to TTM as shown in Table 1. Self-efficacy measures To measure self-efficacy for exercise, we employed the scale made by Sallis et al. 15), and translated it from English into Japanese that was checked by an English specialist. The scale was composed of the following 3 items: (1) set aside time to exercise; (2) be able to exercise when feeling sad or under stress and (3) be able to exercise when family or social demands are great. They were presented via a 5-point Likert scale as follows. 5=agree to, 4=agree to if anything, 3=cannot say which, 2=not agree to if anything and 1=not agree to. Perceived benefit of and barriers to exercise scale To detect benefits and barriers regarding exercise, we used the perceived benefits of and barriers to exercise scale made by Myers and Roth 10). It was translated from English into Japanese and checked by an English specialist. The scale was composed of 48 (24 benefit and 24 barrier) items. They were presented via a 5-point Likert scale like the above-mentioned self-efficacy measures. Exploratory factor analyses were performed to clarify the factor structure of the scale. Because we assumed that there might be a relationship between variables, a maximum likelihood estimation with promax rotation was used as a method of factor extraction. The initial eigenvalues for the extracted factors were greater than 1. The criteria for inclusion of an item on a given subscale were 0.40 or higher with loading on only one subscale. And confirmatory factor analyses were performed with a maximum likelihood estimation to confirm and determine the best-fitting model made on the basis of the results of exploratory factor analyses. Model fitness was assessed by goodness-of-fit test including the chi-square statistics, Akaike Information Criterion (AIC), Comparative fit index (CFI), etc. To determine the reliability of the factors, the internal consistency was calculated for each of the resulting factors by using the Cronbach s Alpha reliability coefficient. Age was categorized into 4 groups (20s, 30s, 40s and 50s) and chi-square was conducted to test the relationship between age and the physical activity/exercise stage. Tukey s HSD was used to follow-up one-way analysis of variance (ANOVA) to examine the relationship between age and psychological determinants (self-efficacy and perceived benefit and barriers), and between the stage of readiness and psychological determinants. A P value of < 0.05 was considered to be statistically significant. All statistical analysis was conducted with SPSS version 10.1 and Amos version 4 for Windows (SPSS Inc. Tokyo. Japan). Results Table 2 shows the characteristics of the study population for age, occupational status, education, working time per day (hrs) and classification of levels of physical activity. The mean age and standard deviation was 43.5 ± Seventy-one percent of the subjects were factory workers, 72% had an education level at least high school, and 65% worked 8 h per day. Seventy-two Table 2. Demographics of the study population Variables n (%) Age (yrs) (14.4) (17.9) (30.8) (36.8) Occupational status office worker 58 (28.9) factory worker 143 (71.1) Education high school 145 (72.1) college and professional school 37 (18.4) university and graduate school 19 (9.5) Working time per day (hrs) 7 44 (21.9) (64.7) 9 27 (13.4) Classification of levels of physical activity light 144 (71.6) moderate 43 (21.4) slightly heavy 13 (6.5) heavy 1 (0.5)

4 18 J Occup Health, Vol. 45, 2003 Table 3. Maximum likelihood method with promax rotation of the perceived benefits and barriers Factor and item Factor loading and α Factor and item Factor loading and α Benefit factors Barrier factors Health α=0.93 Physical α=0.85 Improves strength 0.95 Uncomfortable 0.75 Increases metabolism 0.93 Causes sore muscles 0.71 Improves cardiovascular fitness 0.88 Get hot and sweaty 0.69 Helps to look good 0.84 Too fatigued 0.68 Improves health 0.79 Too uncoordinated 0.68 Improves flexibility 0.59 Too boring 0.66 Psychological α=0.89 Look silly 0.51 Gives peace of mind 0.95 Don t like to exercise alone 0.50 Gives time to think 0.88 Too lazy 0.47 Gives confidence in self 0.86 Too inconvenient 0.41 Helps relax 0.76 Specific obstacles α=0.85 Improves attitude towards life 0.67 Interferes with social life 0.90 Helps cope better with pressure 0.52 Interferes with school 0.86 Lifts one s spirits 0.46 Friends do not exercise 0.60 Improves appearance 0.44 Bad weather 0.59 Social α=0.89 Family does not encourage 0.58 Provides a way to meet people 0.88 Medical problems 0.56 Builds companionship 0.83 Time α=0.82 Good to do with friends 0.80 Not enough time 0.82 Feel more energetic 0.41 Too busy 0.74 Weight control α=0.92 Too much work 0.73 Maintain proper body weight 0.94 Too tired 0.61 Helps stay in shape 0.71 Family obligations 0.59 Helps lose weight 0.62 Except items Except items Is competitive Takes too much discipline Helps feel better in general No convenient places Improves self-image Interferes with work percent and 21% engaged in light and moderate level of physical activity in daily life, respectively, that is most of the subjects engaged in sedentary or standing occupations. Table 1 shows the physical activity/exercise stage of the study population. Twenty-three percent of the subjects were in the precontemplation stage, 39% in the contemplation stage, 29% in the preparation stage, 4% in the action stage, and 6% in the maintenance stage. All women in the action and maintenance stages engaged in moderate physical activity, but none of them did vigorous exercise. Since the proportions of the study population in the action and maintenance stages of TTM were small, we combined them for analysis. In the perceived benefit and barrier scale, exploratory factor analyses were performed, and the maximum number of the models in which initial eigenvalues were greater than 1 was 10. But 10-, 9- and 8-factor model were not suitable for further analysis because only one or two items were detected in these factors, so that they cannot provide better interpretation of the data. Hence confirmatory factor analyses were performed in the 7- and 6-factor models and the best-fitting model was the 7-factor model according to the result of the goodnessof-fit test. Then the items were classified into 7 factor categories (4 benefits and 3 barriers), by which 61.5% of total variance was explained. As Table 3 shows, 7 factors contain: (1) health benefit (6 items, Chronbach s Alpha=0.93, the percentage accounting for total variance of factor 1 was 25.2%); (2) psychological benefit (8 items, Chronbach s Alpha=0.89, the percentage accounting for total variance of factor 2 was 13.7%); (3) social benefit (4 items, Chronbach s Alpha=0.89, the percentage accounting for total variance of factor 3 was 3.2%); (4) weight control benefit (3 items, Chronbach s Alpha=0.92, the percentage accounting for total variance

5 Yuko NISHIDA, et al.: Psychological Determinants of Physical Activity 19 Table 4. Mean values and differences in self-efficacy and perceived benefits and barriers among the physical activity/exercise stages Physical activity/ exercise stage PC C PR A/M F value Post hoc analysis (n=46) (n=78) (n=58) (n=19) Self-efficacy 2.1 ± ± ± ± ** PC<PR **, PC<A/M ** C<PR **, C<A/M ** Perceived benefit Health 4.0 ± ± ± ± Psychological 3.1 ± ± ± ± Social 3.5 ± ± ± ± Weight control 3.6 ± ± ± ± * PC<C * Perceived barriers Physical 2.6 ± ± ± ± ** PC>PR **, C>PR * Specific obstacles 1.8 ± ± ± ± Time 3.0 ± ± ± ± * C>PR * PC: Precontemplation stage, C: Contemplation stage, PR: Preparation stage, A/M: Action/Maintenance stage * p<0.05, ** p<0.01 (Tukey s HSD) of factor 4 was 2.9%); (5) physical barrier (10 items, Chronbach s Alpha=0.85, the percentage accounting for total variance of factor 5 was 7.5%); (6) specific obstacles barriers (6 items, Chronbach s Alpha=0.85, the percentage accounting for total variance of factor 6 was 5.2%), and (7) time barrier (5 items, Chronbach s Alpha=0.82, the percentage accounting for total variance of factor 7 was 3.7%) Chi-square test indicates that there were no significant relationships among 4 age groups and physical activity/ exercise stages in the population, so that the possibility that age contributed to the variance of stage was excluded. Mean item rating scores were computed by using the self-efficacy scale and the 4 benefit and 3 barrier factors derived from the factor analysis. ANOVA indicates that there were differences in weight control benefit (F=3.72, p<0.05) and in time barrier (F=3.67, p<0.05) among age groups. Subjects in their 20s perceived greater weight control benefit than those in their 30s (p<0.05) and subjects in their 20s perceived less time barrier than those in their 30s (p<0.05), 40s (p=0.071) and 50s (p< 0.05). The relationship between the stage of physical activities/exercise and psychological determinants (selfefficacy, subscales of perceived benefits and barriers) is shown in Table 4. The results revealed that the stage of physical activity/exercise was related to self-efficacy, weight control benefit, physical barrier and time barrier, especially self-efficacy consistently related to the stage of physical activity/exercise. Self-efficacy levels of subjects in the preparation and action/maintenance stages were higher than those in the precontemplation and contemplation stages. Subjects in the contemplation stage perceived greater weight control benefit than those in the precontemplation stage. Subjects in the precontemplation and contemplation stages perceived a greater physical barrier than those in the preparation stage. Subjects in the preparation stage perceived a greater time barrier than those in the contemplation stage. Discussion This is the first attempt to investigate the psychological determinants of the stage of physical activity/exercise in female employees in Japan based on the transtheoretical model of behavior change. The stage distributions for physical activity/exercise showed that 10% of the subjects were in the action and maintenance stages. Such a small proportion of the participants in these 2 stages in our results was probably due to the adoption of both the Centers for Disease Control and Prevention (CDC)/the American College of Sports Medicine (ACSM) guidelines for health benefit 13) and ACSM recommendations 14) as a criteria. CDC/ACSM Guidelines for health benefit 13) defined regular exercise and regular physical activity (action and maintenance stages) as doing moderate physical activity on most, preferably all, days of the week, whereas ACSM Recommendations defined them as doing vigorous exercise 3 to 5 times per week 14). So far, the definition from ACSM Recommendations 14) has been widely used as a criterion in Japan for the survey of regular exercise in a target population. The reason we used both CDC/ACSM Guidelines for health benefit 13) and ACSM Recommendations 14) as criteria was that not

6 20 J Occup Health, Vol. 45, 2003 only vigorous exercise but also moderate physical activity has been demonstrated to be important for disease prevention and health promotion 13). In particular, females have been reported to prefer moderate physical activity to vigorous exercise 1, 8, 11). Our data also showed all women in the action and maintenance stages engaged in moderate physical activity (see Table 1), indicating that the criteria we used might well disclose the true picture of regular physical activity/exercise in female employees. Our data indicated that self-efficacy, weight control benefit, physical barrier and time barrier were psychological determinants of the stage of physical activity/exercise; especially self-efficacy was consistently related to the stage of physical activity/exercise, and the determinants varied with the stage. Therefore, conducting a stage-matched intervention approach to women, especially emphasizing the increase in self-efficacy is important for raising the stage of physical activity/ exercise. Here we would like to discuss the psychological determinants of the stage of physical activity/exercise of the study population and to frame an effective intervention approach to those who are in the precontemplation, contemplation and preparation stages. Individuals in the precontemplation stage generally do not notice that lack of physical activity is a result of the sedentary lifestyle 16). Therefore intervention in the precontemplation stage, that is, let the subjects be conscious of their unhealthy lifestyle and have an interest in doing physical activity and exercise will be the first and a large step toward the contemplation stage or further stages. Women in Japan nowadays are greatly interested in weight control to keep a slender figure, and such a desire for weight control probably arouses their interest in physical activity and exercise. The present results demonstrated that subjects who were perceived as having a weight control benefit were interested in physical activity and exercise, especially subjects in their 20s, but did not adopt physical activity/exercise. Johnson et al. also found that women who reported presently dieting were twice as those exercising 17), indicating that half of these women tend to reduce their weight by using a way other than exercise. It seems that having an interest in weight control alone would not become a motive for adopting physical activity/exercise in women. In the present study, weight control benefit was revealed as a psychological determinant from the precontemplation stage to the contemplation stage. It has generally been considered that a greater emphasis placed on the weight control benefit of physical activity/exercise in the intervention approach would have a good effect on increasing interest in physical activity/exercise among women. Individuals in the contemplation stage are those who understand the need for a behavioral change, but they still maintain their sedentary lifestyle 16). In the present study self-efficacy, physical barrier and time barrier were revealed as the psychological determinants of behavior change from the contemplation stage to the preparation stage, and self-efficacy rose gradually and constantly from the precontemplation stage to the action and maintenance stages, which is consistent with earlier studies 18 20). The difference between the contemplation stage and the preparation stage in self-efficacy was statistically significant, suggesting that self-efficacy is an important determinant among these female employees, and strengthening self-efficacy while individuals increase the stages of physical activity/exercise is imperative for effective intervention, especially among individuals in the contemplation stage. With regard to the physical barrier, we found the main perceived barriers to physical activity/exercise were related to being uncomfortable, getting hot and sweaty, causing sore muscles, indicating that vigorous exercises were a burden to these female employees and they tended to perceive a greater physical barrier than physical benefits from regular exercise. An earlier study showed that women were less likely to participate in moderate to vigorous exercise than men 1, 8, 11), and walking and other forms of moderate activity might be more acceptable to them 11), and a lifestyle physical activity intervention was proved as effective as a structured exercise program in improving physical health 21, 22). With regard to the time barrier, the results revealed that engagement in both work and family obligations were the major reasons for lack of time among the females, which are compatible with the results of earlier studies 17, 23). Women in their 30s, 40s and 50s perceived more time barrier than those in their 20s in our study, possibly indicating that family obligations are additional burdens to them. For women who are holding a job and raising a family, it is difficult to set aside some time to engage in regular exercise. Therefore, when we consider an intervention approach to female employees in the contemplation stage, it is particularly important to let the individuals know that regular moderate physical activity has as many health benefits as vigorous exercise, and physical activity can be created through daily life and work, such as walking or cycling to work and shopping instead of driving to, going up and down the stairs instead of using an elevator, taking a walk with the dog, gardening, doing stretching exercises during a break at work or while watching television at home, etc. This information may assist in enhancing the individuals self-efficacy to influence their physical activity habits in a positive direction. Individuals in the preparation stage are those who wish to change their lifestyle more actively and are doing behavioral changes in their own way 16). The present results showed that although self-efficacy did not approach significance between the preparation and the action/maintenance stages, it was significant between the

7 Yuko NISHIDA, et al.: Psychological Determinants of Physical Activity 21 precontemplation and action/maintenance stages and between the contemplation and action/maintenance stages. It has been reported that there were strong positive relationships between self-efficacy and the stage of behavior change 18 20). As in the contemplation stage, we believed that continuously strengthened self-efficacy for those female subjects in the preparation stage should also be very important in increasing the stage of physical activity/exercise, which also agrees with the recommendation of Oka 16). Health benefit, psychological benefit, social benefit, specific obstacles barrier were not psychological determinants of physical activity/exercise behavior change in our study. Health benefit tended to increase from the precontemplation stage to the preparation stage but we were not able to observe a significant level. It is worth noticing that psychological benefit did not relate with the stage change in our study, and this suggests that the health education method so far applied in Japan, that is, providing information on the health benefits of regular exercise alone is not enough to encourage female employees to adopt a more active lifestyle. It is very needful to further elucidate why these benefits do not relate with the exercise stage among female employees. In our data, specific obstacles barrier contained social support items such as lack of an exercise partner and lack of family support. Some research has revealed that lack of social support was an important barrier to adopting and maintaining exercise 15, 17). On the other hand, Lechner and Vries reported that the social support factor was nearly identical for behavior change in the precontemplation, contemplation, and preparation stages, whereas female subjects in the action stage experienced significantly more social support 19). Nevertheless, no significant relationship was found between social support and the stages of physical activity /exercise in the present study population, and one explanation we consider is that the proportion of subjects in the action and maintenance stages was small and it is not enough to show the effectiveness of social support on the stage change in physical activity/exercise. But we believe that social support is one of the important factors in maintaining physical activity and exercise. Further study is needed to confirm the hypothesis. By factor analysis, we found that no convenient place made only a small contribution to the stage of change among the participants, and this item was therefore omitted from further analysis. This finding suggests that this factor is unlikely to be a perceived barrier to the female employees in our study. But other studies have revealed that the perceived difficulty of access to exercise facilities was an important barrier to adopting and maintaining exercise 11). The difference between our results and the others in the importance of accessible facilities as a perceived barrier might be explained by two considerations: one is that, for women, doing exercise in the facilities would remind the individuals of vigorous exercise that is a stronger perceived barrier to adopting exercise than accessibility of facilities, another one is that engaging in both work and family obligations possibly makes female employees have no time to go to facilities, so no convenient place might not be considered as a perceived barrier for them. Further research is required to elucidate whether the difficulty of access to exercise facilities is a psychological determinant of physical activity/exercise among female employees. Many studies have demonstrated a relationship between regular physical activity/exercise and age among women 1, 2, 8), some of them reported age was associated positively with regular physical activity/exercise 1, 2, 8), but some of them found a negative association 1, 8). The National Nutrition Survey 2) in Japan reported that age was associated positively with regular exercise. Nevertheless, our data showed that age was not related to physical activity/exercise stage. The results might be explained by the fact that subjects in their 30s, 40s and 50s tended to perceive a time barrier more than those in their 20s in our study, and a time barrier may interfere with doing regular physical activity/exercise among female employees in these generations. There are some limitations to this study. First, we employed the criteria of the regular physical activity and exercise according to the CDC/ACSM guidelines 13) and ACSM recommendations 14). And we also used the selfefficacy and perceived benefits and barriers scales to measure the psychological determinants of exercise, but a scale to measure these determinants of physical activity is not available in Japan. There is a need to develop scales to measure regular physical activity for Japanese. Second, the present research was carried out in a limited number of subjects and a limited area. Further study is required to confirm whether the patterns of psychological determinants of physical activity/exercise behavior found in the present study are consistent with those of other groups in the Japanese population. In conclusion, self-efficacy, weight control benefit, physical barrier and time barrier were psychological determinants of the physical activity/exercise stage among the female employees in our study, and especially there was consistently a relationship between self-efficacy and the stage of physical activity/exercise behavior. Our data suggest that health education for Japanese female employees requires that health professionals should provide support for strengthening self-efficacy, show practical ways to increase physical activity in daily life and provide broad and accurate information showing that vigorous exercise has good effects on health, and other physical activity also does. The criteria of regular physical activity and exercise we used are considered to be very helpful in allowing the health professionals to

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