Journal of Occupational Health
Online ISSN : 1348-9585
Print ISSN : 1341-9145
ISSN-L : 1341-9145
Originals
The practice of active rest by workplace units improves personal relationships, mental health, and physical activity among workers
Ryoma MichishitaYing JiangDaisuke AriyoshiMarie YoshidaHideko MoriyamaHiroshi Yamato
Author information
JOURNALS FREE ACCESS FULL-TEXT HTML

2017 Volume 59 Issue 2 Pages 122-130

Details
Abstract

Aim: This study was designed to clarify the effects of active rest, with a focus on the practice of short-time group exercise by workplace units, on personal relationships, mental health, physical activity, and work ability among workers. Methods: Fifty-nine white-collar workers (40 males and 19 females) performed our active rest (short-time exercise) program, which consists of warm-up, cognitive functional training, aerobic exercise, resistance training and cool-down for 10 minutes per day, 3 times per week during their lunch breaks for 10 weeks. Participants from a workplace unit were randomly allocated to the intervention (five workplaces, n=29) or control groups (six workplaces, n=30). The participants' anthropometric measurements, and their Profile of Mood States (POMS) 2, Brief Job Stress Questionnaire (BJSQ), physical activity levels and Work Ability Index were examined at the baseline and after the 10-week intervention. Results: After 10 weeks, physical activity levels, especially the time spent in moderate and vigorous intensity, increased in the intervention group (p<0.05). The items of "vigor-activity" and "friendliness" improved in POMS 2, while "vigor," "interpersonal stress," "support from superiors, colleagues, and family/friends," and "job satisfaction" improved in BJSQ in the intervention group (p<0.05). In the intervention group, the number of exercise participation was positively correlated with the change in "vigor-activity" in POMS 2 (r=0.467, p=0.011). Conclusions: These results suggest that the practice of active rest by workplace units is important for improving personal relationships, mental health, and physical activity among workers.

Introduction

The concept of "active rest" has been proposed in recent times1,2). This concept is based on the hypothesis that moderate exercise allows individuals to recover from fatigue more effectively than lying down1,2). It is well shown that many workers spend their lunch breaks playing games or spending e-mails3). It is hypothesized that if workers perform exercise during their lunch breaks instead of playing games or spending e-mails, then they will be able to reduce their fatigue and increase their work efficiency. Furthermore, the introduction of active rest in the workplace may elevate health awareness, increase physical activity during work or leisure-time, and will be expected to have a health promotion effect among workers. In addition to improving physical health such as decreasing body weight and blood pressure, exercise training has been shown to improve mental health4-6). The performance of group exercise in the same workplace is expected to improve workplace communication7,8). Namely, the performance of group exercise in the same workplace may make it easier for workers to obtain support from supervisors and colleagues. We hypothesized that improved communication within the workplace would have beneficial effects on personal relationships, mental health and work ability because the performance of group exercise in the same workplace is expected to improve workplace communication7,8). However, at present, the effects of the practice of active rest by workplace units on personal relationships, mental health, physical activity, physical health and work ability among workers have not been investigated.

We recently produced a short-time exercise program consisting of warm-up, cognitive functional training, aerobic exercise, resistance training and cool-down periods, which can be completed within 10 minutes with the aim of preventing metabolic and locomotive syndromes, creating an opportunity for individuals to develop exercise habit. If the effects of the practice of active rest by workplace units can be clarified, it may show that the performance of group exercise within the same workplace during lunch breaks can help to improve personal relationships, mental health, physical activity, physical health, and work ability. We therefore hypothesized that the practice of active rest by workplace units may help to maintain or improve these factors. This study was designed to clarify the effects of the practice of active rest by workplace units on personal relationships, mental health, physical activity, physical health, and work ability among workers.

Participants and Methods

Participants and study design

The targeted company in this study is composed of 31 workplaces and 931 employees. Participants were recruited via workplace advertisements and from 11 workplaces and 63 white-collar workers who voluntarily participated in our active rest program. Participants with a history of severe complications such as cardiovascular or cerebrovascular diseases, were excluded from this study. The information about medical history, taking medications, smoking and alcohol intakes were confirmed using self-administered questionnaires before intervention. In the present randomized controlled trial, participants were randomly allocated in workplace units to the intervention (n=30) and control groups (n=33). One participant in the intervention group and three participants in the control group did not complete the program because they were transferred to another department. Thus, 59 participants (male, n=40; female, n=19; age, 40.9±9.2 years; body mass index [BMI], 22.8±2.9 kg/m2) completed the intervention. The intervention group included 29 participants (5 workplaces, male, n=19; female, n=10; age, 40.8±9.8 years; BMI, 23.1±3.2 kg/m2), while the control group included 30 participants (6 workplaces, male, n=21; female, n=9; age, 41.1±8.6 years; BMI, 22.5±2.5 kg/m2). A diagram of participants included in this study is shown in Fig. 1.

Fig. 1.

Flow chart of participants included in the study

After the baseline assessments, the intervention group started the 10-week active rest program and the control group continued their normal daily life and served as controls. Participants' anthropometric indices, blood pressure levels, physical activity levels, mood states, job-related stress levels, and work ability were evaluated before the intervention and after the 10-week intervention (Fig. 2).

Fig. 2.

Protocol of our active rest intervention study

In this randomized controlled trial, participants within a workplace unit were randomly allocated to the intervention and control groups.

Anthropometry indices, blood pressure, physical activity levels, mood states, job-related stress and work ability were evaluated before intervention and after the 10-week intervention.

All participants gave their informed consent for participation in this study after agreeing with its purpose, methods, and significance. This study conformed to the Declaration of Helsinki and was approved by the Ethics Committee of the University of Occupational and Environmental Health, Japan (No. H27-068).

Active rest program (10 minutes lunch fitness®)

Participants performed the 10 minutes lunch fitness® program 3 times per week for 10 weeks (a total of 29 times). The program takes 10 minutes and was performed during a lunch break. This short-time exercise program consisted of warm-up (stretching), cognitive functional training, aerobic exercise, body weight resistance training and cool-down components. The program could be completed within 10 minutes. The 10 minutes lunch fitness® program was created by the Society of 10 Minutes Lunch Fitness (http://10mlf.com) with the aim of preventing metabolic and locomotive syndromes, and promoting an opportunity for individuals to develop exercise habit9). This exercise program is the exercise to feel moderately for degree to sweat. The exercise training was practiced under the supervision of a fitness instructor in a closed conference room so that the control group would not be able to observe it.

Anthropometry and physical activity level measurements

Anthropometry and blood pressure measurements were performed after at least two hours of fasting (at ten or fifteen o'clock). Subjects' height and body weight were measured and their BMI was calculated as the ratio of the body weight (kg) to height squared (m2). The waist circumference was measured at the level of the umbilicus. The body fat mass and lean body mas were measured using the bioelectrical impedance method (DC-320, TANITA Inc., Tokyo, Japan). Blood pressure (HEM-7080IT, OMRON Inc., Kyoto, Japan) was measured in the right arm with the subject sitting in a chair, after more than 5 minutes of rest, and expressed as the average of triplicate measurements.

Physical activity levels were assessed using a single-axis accelerometer (Life-Corder GS, Kenz, Nagoya, Japan), which is shown to be a valid method of determining the energy expenditure associated with a respiratory chamber and doubly labeled water10,11). The use of an accelerometer and the procedure for wearing an accelerometer are same as that in previous publications10-12). Each participant wore an accelerometer on a belt at the waist level during the intervention period, except while sleeping or bathing. After the measurements were taken, the device was retrieved and data were downloaded to a personal computer. To minimize any potential influence of the device on the participants' physical activity levels and to assess the typical physical activity levels, data from the first and last days were discarded. In addition, only data from the days on which the accelerometer was worn for ≥8 hours per day in the last seven days before the completion of the intervention period were analyzed. Based on the frequency and magnitude of acceleration, the total inactivity time (<1.1 METs: acceleration intensity, <1), or the time spent in light (1.1-2.9 METs: acceleration intensity, 1-3), moderate (3.0-5.9 METs: acceleration intensity, 4-6), or vigorous intensity (≥6.0 METs: acceleration intensity, 7-9) was evaluated.

Assessment of mood states and job-related stress

The mood states of participants were assessed using the Japanese translation of the Profile of Mood States second edition (POMS 2®, KANEKOSHOBO Inc., Tokyo, Japan)13-15). POMS 2 is a mood inventory, which contains 65 items (adjectives) that describe seven different moods as follows: "Anger-hostility", "confusion-bewilderment", "depression-dejection", "fatigue-inertia", "tension-anxiety", "vigor-activity" and "friendliness". Participants were asked to indicate their mood states on a five-point scale ranging from "not-at-all" to "extremely" during the previous 1-week period. The sum of scores was calculated for each subscale. The Total Mood Disturbance (TMD) score was calculated as follows: ([ "anger-hostility" + "confusion-bewilderment" + "depression-dejection" + "fatigue-inertia" + "tension-anxiety" ]- "vigor-activity" ). It is well known that the POMS 2 allows for detailed evaluation of mood changes12-14).

The participants' job-related stress was evaluated using the Brief Job Stress Questionnaire (BJSQ), which was developed and validated by the Ministry of Health, Labour and Welfare of Japan16). BJSQ was created to identify employees who experience mental problems at an early stage. BJSQ has been widely used in research and practice in the field of workplace mental health in Japan17). BJSQ is composed of 57 items and based on a four-point Likert scale that ranges from "strongly disagree" to "strongly agree". This questionnaire consists of the following subscales: Job stressors (17 items: E.g., quantitative job workload, qualitative job workload, interpersonal stress, and job control), job stress reaction (29 items: E.g., psychological and physical stress response), social support (9 items: E.g., support from superiors, colleagues, and family/friends), and the participants' satisfaction with their job and daily life (2 items).

Assessment of work ability

The participants' work ability was assessed using the Work Ability Index (WAI) Japanese edition18). WAI, which was developed by the Finnish Institute of Occupational Health, is often used to estimate work ability. It is well known that good work ability is associated with high-quality work and job satisfaction19). AT present, WAI is considered to be related to several cardiovascular risk factors20-23). WAI consists of the following seven dimensions: Perceived work ability in comparison to lifetime best, assessment of physical and mental demands of work colleagues, diagnosed diseases, limitations in work due to disease, sick leave, work ability prognosis, and psychological resources. WAI is calculated as the sum of ratings of each dimension (range: 7-49 points).

Statistical analyses

Data were expressed as the mean and standard deviations (SD). The StatView J-5.0 software program (SAS Institute, Cary, NC, USA) was used for all statistical analyses. Intergroup comparisons were performed using the Mann-Whitney's U-test for continuous variables and the chi-squared test for categorical variables. Comparisons of data at the baseline and after the 10-week intervention were performed using a Wilcoxon signed-ranks test for continuous variables. Differences in the changes in anthropometric values, as well as physical activity levels, mood states, job-related stress levels, and work ability of the intervention and control groups were included in the two-way repeated measure analysis of variance for the intervention and groups × time interactions. A simple linear regression analysis was performed to determine the associations between continuous variables. Probability values were determined using two-sided testing and the probability values of <0.05 were considered to indicate statistical significance.

Results

Table 1 shows the participants' baseline characteristics in both the intervention and control groups. There were no significant differences in the baseline characteristics of the two groups. The mean number of exercise participation performed by participants in the intervention group was 18.2±8.4 times (range: 2-29 times) (a total of 29 times). Fig. 3 shows physical activity levels at the baseline and after the 10-week intervention in both the intervention and control groups. The time spent in moderate and vigorous intensity increased in the intervention group (p<0.05, respectively). A significant interaction effect for group × time was seen in tmoderate and vigorous intensity between the two groups (p<0.05).

Table 1. The participants' baseline characteristics in the intervention and control groups
Intervention group
(5 workplaces, n=29)
Control group
(6 workplaces, n=30)
p value
The data are expressed as the mean ± standard deviation and the number of participants.
Age (years) 40.8±9.8 41.1±8.6 0.910
Sex (males/females; n, %) 19 (65.5)/10 (34.5) 21 (70.0)/9 (30.0) 0.713
Taking medications (n, %) 3 (10.3) 4 (13.3) 0.723
Smoking (n, %) 8 (27.6) 7 (23.3) 0.708
Alcohol (n, %) 22 (75.8) 17 (56.7) 0.119
Fig. 3.

Comparisons of physical activity levels in the intervention and control groups at the baseline and after the 10-week intervention

Data are expressed as the mean ± standard deviation.

A) number of steps, B) inactive time, C) time spent in light intensity, D) time spent in moderate intensity, and E) time spent in vigorous intensity

Open circle; intervention group, filled square; control group

*; p for Wilcoxon signed-ranks test, <0.05, in comparison to values before intervention in each group.

Table 2 shows anthropometric indices, mood states, job-related stress, and work ability at the baseline and after the 10-week intervention in the intervention and control groups. After 10 weeks, the items of "fatigue-inertia" decreased and "vigor-activity" and "friendliness" in POMS 2 increased in the intervention group (p<0.05). A significant interaction effect for group × time was seen in the items of "fatigue-inertia", "vigor-activity" and "friendliness" in POMS 2 between the two groups (p<0.05). The BJSQ items of "interpersonal stress" decreased and "vigor," "support from superiors, colleagues and family/friends," and "satisfaction with job/daily life" increased in the intervention group (p<0.05). A significant interaction effect for group × time was seen in the BJSQ items of "interpersonal stress," "vigor," "support from superiors, colleagues and family/friends," and "satisfaction with job/daily life" between the two groups (p<0.05).

Table 2. The anthropometric indices, mood states and job-related stress at baseline and after the 10 weeks in the intervention and control groups
Intervention group
(5 workplaces, n=29)
Control group
(6 workplaces, n=30)
Group×time interaction
(p value)
Baseline 10 weeks p value Baseline 10 weeks p value
The data are expressed as the mean ± standard deviation.
BMI, body mass index; POMS, Profile of Mood States; TMD, total mood disturbance; BJSQ, Brief Job Stress Questionnaire.
Anthropometric indices and blood pressure
BMI (kg/m2) 23.1±3.2 23.2±3.2 0.466 22.5±2.5 22.6±2.3 0.179 0.595
Body fat mass (kg) 15.7±4.8 15.6±4.8 0.829 14.9±3.9 15.0±4.0 0.706 0.649
Lean body mass (kg) 48.0±9.8 48.3±9.8 0.210 48.4±8.7 48.6±8.6 0.139 0.607
Waist circumference (cm) 82.9±10.8 82.0±9.8 0.375 81.2±7.4 81.4±8.0 0.502 0.281
Systolic blood pressure (mmHg) 119.9±16.3 122.4±17.1 0.127 124.1±23.1 121.7±18.1 0.389 0.187
Diastolic blood pressure (mmHg) 76.1±15.2 78.0±13.2 0.090 77.7±13.5 77.5±10.6 0.830 0.343
POMS 2 score
Anger-hostility (points) 7.1±5.4 7.1±5.4 0.972 6.5±5.1 5.8±5.7 0.323 0.324
Confusion-bewilderment (points) 14.2±6.5 13.2±6.7 0.081 12.1±6.7 11.1±6.7 0.090 0.913
Depression-dejection (points) 8.4±7.7 8.5±8.3 0.605 7.8±8.2 7.5±7.2 0.761 0.840
Fatigue-inertia (points) 7.8±4.5 6.0±3.6 0.007 6.6±5.6 6.7±5.5 0.648 0.042
Tension-anxiety (points) 12.9±6.6 11.8±6.3 0.113 12.1±6.5 11.5±7.7 0.247 0.866
Vigor-activity (points) 11.5±6.4 13.4±6.2 0.008 12.9±8.4 13.0±7.8 0.920 0.046
Friendliness (points) 10.5±3.4 11.6±3.9 0.010 10.8±4.2 10.3±3.6 0.131 0.001
TMD score (points) 39.0±31.3 33.4±30.9 0.018 31.6±26.9 29.5±28.2 0.096 0.279
BJSQ score
Job stressor
Quantitative job workload (points) 3.1±0.8 3.0±0.7 0.272 3.1±1.1 3.3±1.1 0.236 0.358
Qualitative job workload (points) 2.9±0.8 2.9±0.9 0.799 3.1±1.0 3.3±0.8 0.256 0.219
Physical demands (points) 3.6±0.6 3.4±0.6 0.098 3.7±0.5 3.7±0.5 0.990 0.294
Interpersonal stress (points) 3.2±0.8 2.9±0.5 0.008 3.2±0.8 3.2±0.8 0.686 0.019
Poor workplace environment (points) 2.6±1.0 2.8±0.9 0.196 2.8±1.0 3.1±0.9 0.272 0.634
Job control (points) 3.3±0.6 3.4±0.7 0.445 3.7±0.7 3.7±0.9 0.767 0.545
Skill utilization (points) 3.0±0.7 2.9±0.7 0.161 3.0±0.8 2.9±0.7 0.917 0.436
Job aptitude (points) 2.8±0.9 2.9±0.9 0.715 3.2±1.0 3.0±0.8 0.239 0.328
Worthwhileness of working life (points) 2.9±0.9 3.0±0.9 0.361 3.1±1.2 3.0±1.0 0.248 0.144
Job stress reaction
Vigor (points) 3.0±1.1 3.5±1.3 0.002 3.2±1.2 3.2±0.8 0.610 0.021
Irritability (points) 3.4±1.1 3.4±1.1 0.991 3.2±1.0 3.4±1.0 0.301 0.204
Fatigue (points) 3.0±0.8 3.1±0.8 0.554 3.4±1.1 3.2±1.1 0.374 0.382
Anxiety (points) 3.0±0.8 3.2±1.0 0.142 3.3±1.1 3.3±1.0 0.861 0.703
Depression (points) 3.2±1.3 3.3±1.3 0.477 3.5±1.3 3.3±1.1 0.285 0.324
Physical complaint (points) 2.9±0.8 2.8±1.0 0.310 3.2±0.7 3.4±1.0 0.164 0.152
Social support
Support from superiors (points) 3.4±1.0 3.9±0.7 0.019 3.2±1.0 3.0±1.1 0.263 0.021
Support from colleagues (points) 3.1±0.8 3.4±0.7 0.018 2.8±1.0 2.7±0.9 0.594 0.012
Support from family/friends (points) 3.4±1.4 3.9±1.0 0.005 3.4±1.3 3.4±1.5 0.875 0.008
Satisfaction for job/daily life (points) 3.2±0.8 3.4±0.8 0.027 3.4±1.0 3.2±0.8 0.388 0.034
Work Ability Index (points) 42.3±5.0 41.6±5.1 0.414 42.7±5.1 41.8±4.3 0.242 0.906

Fig. 4 shows the association between the number of exercise participation and change in the item of "vigor-activity" in POMS 2, as determined by a simple regression analysis in the intervention group. In this analysis, the change in the item of "vigor-activity" in POMS 2 was a dependent variable and the number of exercise participation during the intervention period was an independent variable. The number of exercise participation was positively correlated with the change in the item of "vigor-activity" (r=0.467, p=0.011).

Fig. 4.

Association between the number of exercise participation and the change in item of "vigor-activity" in POMS 2, as determined by a simple regression analysis in the intervention group.

In this simple regression analysis, the change in the item of "vigor-activity" in POMS 2 was a dependent variable and the number of exercise participation during the intervention period was an independent variable. The number of exercise participation was positively correlated with the change in the item of "vigor-activity" in POMS 2 (r=0.467, p=0.011).

Discussion

The major finding of this study was that the items of "friendliness" in POMS 2 while "interpersonal stress" and "support from superiors, colleagues and family/friends" in BJSQ improved in the intervention group. Moreover, a significant interaction effect for group × time was seen in these mood states and job-related stress levels between the intervention and control groups.

Several studies have reported the effects of group exercise on physical and mental health states7,8,24). Erime et al.7) revealed that participation in club and team sports resulted in greater improvements in psychosocial health outcomes than that in individual exercise. In an intervention study24) that compared the psychological effects of group and individual exercise programs on middle-aged and older adults, subjects who participated in a program that involved group exercise had a higher self-assessment of activity, enjoyment, achievement, satisfaction and self-recognition scores than those who only participated in an individual exercise program. However, the effects of the practice of active rest by workplace units on personal relationships have not previously been studied. Regrettably, the participants' position and personal relationships in each of the workplace were unclear to secure anonymity of the individual. Therefore, we were not able to elucidate the mechanisms underlying the effect of active rest by workplace units on personal relationships. In this study, participants were randomly allocated within a workplace unit to both the former and latter intervention groups, and members of the workplace unit participated in exercise training during their lunch breaks. Thus, the effects of active rest on personal relationships in workplace may have results from the performance of group exercise in the same workplace during the participants' lunch breaks. If we recommended the 10 minutes of exercise from the viewpoint of occupational injury and compelling force, then companies may be addressed within the working time. Based on our results, we believe that it is important to perform exercise during lunch breaks from the viewpoint of occupational health. The current findings suggest that the performance of group exercise within a workplace during lunch breaks may be useful for improving personal relationships of workers, especially those related to "interpersonal stress," and "support from superiors, colleagues, and family/friends".

It is well known that in addition to improving physical health, exercise training also improves mental health4-6). Our previous community-based lifestyle modification studies reported that leisure-time exercise and walking or cycling to work were associated with improved mental health states, as evaluated by Genera Health Questionnaire (GHQ)4). Furthermore, it has been previously demonstrated that job satisfaction can be effectively improved by lifestyle modification intervention5). Watanabe et al.25) investigated the associations between exercise habit and job resource and vigor scales, and showed that job resource and vigor scales were positively correlated with exercise habit in 4,543 employees. In this study, the items of "vigor-activity" in POMS 2, "vigor" and "job satisfaction" in BJSQ also improved in the intervention group. This finding is consistent with the results of previous studies. Moreover, in this study, participants performed our short-time exercise program for 10 minutes per day, 3 times per week. However, at present, it is still unknown whether the performance of short-time exercise training by workplace units during lunch breaks is effective for improving the mental health of workers. Interestingly, our results revealed that the number of exercise participation was positively correlated with the change in the item of "vigor-activity" in POMS 2. Thus, the results of this study were considered to support the possibility that the performance of active rest by workplace units during lunch breaks had a cumulative effect despite the short time of the exercise training, and that this intervention may be effective for improving workers' vigor and job satisfaction.

On the other hand, physical activity levels, especially the time spent in moderate and vigorous intensity, increased in the intervention group. Moreover, in the control group, the inactive time decreased and the number of steps and time spent in light intensity increased. The use of stairs during work and leisure-time has been reported to increase due to behavioral changes in subjects who wear a pedometer26,27). Thus, in the control group, the decrease in inactive time, and the increase in the number of steps and time spent in light intensity may have been influenced by the use of a pedometer. However, we showed that physical activity levels, especially the time spent in moderate and vigorous intensity increased in the intervention group. Firestone et al.28) observed that encouragement of group exercise is an effective strategy for increasing leisure-time physical activity among adults. Therefore, the results of this study demonstrate that the performance of group exercise within a same workplace during workers' lunch breaks may also be important for increasing the physical activity of moderate-to-vigorous intensity, and confirm the hypothesis that the introduction of active rest within the workplace elevates health awareness, increases physical activity during work, and leisure-time among workers.

Study limitations and implications for occupational health

This study is associated with several limitations. First, the study population and workplace were small, and was predominantly composed of white-collar workers with no any health complications. It therefore remains unclear whether our findings are applicable to workers in other occupations or those with health complications. Moreover, we would not have to perform a comparison of each parameter in the workplace units because the study population in each of the workplace was small. In addition, even though there is an interactive effect in some of many variables, the difference between intervention and control groups at 10 weeks was small. Second, we assessed the mood states and job-related stress using POMS 2 and BJSQ. However, we were unable to clarify from our results whether these were involved in the mechanisms underlying the improvement in personal relationships and mental health that were observed in workers who practiced active rest. Third, although the anthropometry and blood pressure were measured at ten or fifteen o'clock, we were not able to unify the timing of these measurements. Fourth, this study could not be considered to remove the physical activity data during exercise training to clarify the increase in work and leisure-time physical activity. Therefore, we could not clarify the direct influence of an increase in physical activity only by work and leisure-time. Fifth, adherence to exercise was insufficient in the intervention group (18.2±8.4 times). Finally, our study period was only 10 weeks, which was insufficient follow-up for evaluating the effects of active rest on parameters that reflect physical health, such as body weight and blood pressure.

However, despite these limitations, this was the first study to evaluate the effects of active rest by workplace units on personal relationships, mental health and physical activity among workers. The 10 minutes lunch fitness® program was created with the aim of disease prevention and promoting an opportunity for individuals to develop exercise habit, and its safety has been confirmed9). In this study, adverse events during the intervention period were not observed. Therefore, the possibility of contamination of intervention is considered to be extremely low. In several recent studies, it has been clearly demonstrated that group exercise can effectively improve mental health through an increase in physical activity, as well as improvement in psychological factors and social relationships7,8,24,28). Thus, the results of this study demonstrate the effects of the practice of active rest by workplace units, and may confirm the hypothesis that the performance of group exercise within the same workplace during the workers' lunch breaks helps to improve their personal relationships, mental health, and physical activity. Given our present findings, we believe that it is necessary to promote the practice of active rest by workplace units to promote the workers' health. Further investigation in a larger population, including population of workers in other occupations or with health complications, will be necessary to more precisely clarify the mechanisms underlying this association and the implications for occupational health.

Conclusions

This study was designed to clarify the effects of the practice of active rest by workplace units on personal relationships, mental health, physical activity, and work ability among workers. After 10 weeks, physical activity levels, especially the time spent in moderate and vigorous intensity increased in the intervention group. The items of "vigor," "interpersonal stress," and "support from superiors, colleagues, and family/friends" improved in the intervention group. These results suggest that the practice of active rest by workplace units is useful for improving personal relationships, mental health, and physical activity among workers.

Acknowledgments: We would like to thank Mr. Katsutoshi Arie, Naonori Tsuchiya and the staff members of the Seiko Electric Co., Ltd., as well as the fitness instructors of the Society of 10 Minutes Lunch Fitness® for their assistance with data evaluation. We are grateful to the participants of this study. This work was supported by a grant from the Meiji Yasuda Life Foundation of Health and Welfare.

Conflicts of interest: In this study, two authors (Moriyama H and Yoshida M) who are officials of the Society of 10 Minutes Lunch Fitness are included as the coauthors. Hideko Moriyama is the director of the Society of 10 Minutes Lunch Fitness and she created and offered this exercise program. Marie Yoshida is an official employee of the Society of 10 Minutes Lunch Fitness and she contributed to recruitment of subjects. There was no cost burden for subjects because it was conducted by our research funding to clarify the effects of active rest on personal relationships, mental health, physical activity, and work ability among workers. The salary of such fitness instructors were paid by the Society of 10 Minutes Lunch Fitness. None of the above two coauthors (Moriyama H and Yoshida M) had a role in data collection, data management, or analysis in this study. None of the other authors have any conflicts of interest to declare in association with this study.

References
 
2017 by the Japan Society for Occupational Health
feedback
Top