Appropriately Addressing Too Much Sitting as a Public Health Issue: Content Analysis of Coverage in the Five Major National Japanese Newspapers.

Recent international public health guidelines now address reducing and breaking up time spent sitting (sedentary behavior). Japanese people spend considerable time sitting in workplaces and other contexts. With potential future public health guidelines in Japan, there is the need for greater public awareness of the importance of reducing sedentary time and of practical ways to do so. From the five major Japanese national newspapers, articles on sedentary behavior published between 2000 and 2021 were identified and coded for content analysis, including the main topic of the article, population group, sedentary behavior context or domain, health outcome, and solutions for reducing sedentary time. There were 53 articles identified, with sedentary behavior being the main topic in 22; workers as a population group appeared in 20 articles and workplaces as a domain in 22. More than 70% mentioned health influences, but fewer than 60% mentioned solutions. Further to informing the public about adverse health influences and consequences for workers and workplaces, there is also the need for improved coverage of the broader benefits of reducing sitting time, sedentary behavior among older adults and children, sitting in all aspects of daily life, and, importantly, considering public health guidelines and solutions for reducing prolonged sitting.

Association of Eicosapentaenoic and Docosahexaenoic Acid Intake with Low Birth Weight in the Second Trimester: The Japan Pregnancy Eating and Activity Cohort Study.

This study examined the association of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake during the second trimester with low birth weight (LBW) in pregnant Japanese women and was conducted in conjunction with the Japan Pregnancy Eating and Activity Cohort (J-PEACH) study. The study included 504 pregnant women from four Japanese sites. During the second trimester (14-27 weeks), the participants filled out a self-administered questionnaire assessing the frequency of DHA and EPA supplement intake in the past month, as well as a brief-type self-administered diet history questionnaire (BDHQ). The analysis involved data from two time points: responses to the BDHQ and infant data at birth. In total, 471 and 33 participants were classified into the normal birth weight and LBW groups, respectively. The participants were divided into high-, medium-, and low-intake groups based on their total dietary and EPA and DHA supplementary intakes. The Cochran-Armitage trend test was used to analyze the data; the prevalence of LBW was higher in the low-intake group (p = 0.04). There was no significant sex-based trend (p = 0.27 and p = 0.35). In Japanese women, low dietary and supplementary EPA and DHA intake until the second trimester were risk factors for LBW.

Prevalence and sociodemographic correlates of urinary incontinence in Japanese women: A web-based cross-sectional study.

BACKGROUND: Epidemiological studies on urinary incontinence that used a validated international standard questionnaire are limited in Japan, and few studies have examined the sociodemographic and behavioral correlates of urinary incontinence. OBJECTIVE: The aim of this study was to estimate the prevalence of urinary incontinence according to the Japanese version of the International Consultation on Incontinence Questionnaire-Short Form, and its sociodemographic and behavioral correlates among Japanese women. DESIGN: A web-based cross-sectional study. METHODS: A randomly sampled cross-sectional Internet survey was conducted in Japan among 3030 women aged 20-64 years. The International Consultation on Incontinence Questionnaire-Short Form score, sociodemographic, body mass index, medical and childbirth history, practice of pelvic floor muscle training, and medical care use were obtained. Descriptive statistics, the chi-square test, and forced-entry logistic regression analysis were used in data analysis. RESULTS: Participants' average age was 43.4 years, and the response rate was 32.9%. The prevalence of urinary incontinence was 25.5%, and it increased with age. Stress urinary incontinence was the most common subtype (57.4%), followed by urge urinary incontinence (20.3%) and mixed urinary incontinence (16.7%). Less than 5% of those with urinary incontinence had experience with pelvic floor muscle training and medical care use. Middle-aged and older (p < 0.001), overweight and obesity (p < 0.001), vaginal delivery status (p < 0.001), low back pain (p = 0.008), and previous pelvic floor muscle training engagement (p < 0.001) were significantly associated with urinary incontinence. CONCLUSION: Increasing population awareness of urinary incontinence from an early age and developing effective interventions for the identified at-risk groups, such as the middle-aged and older, those with overweight and obesity, and those with previous pregnancies, are urgently needed.

Neighborhood socioeconomic status and cardiometabolic risk: mediating roles of domain-specific physical activities and sedentary behaviors.

PURPOSE: We examined the potential mediating roles of domain-specific physical activities and sedentary behaviors in the relationship between area-level socioeconomic status (SES) and cardiometabolic risk. METHODS: Data were from the 2011/2012 Australian Diabetes, Obesity and Lifestyle study (n = 3431). The outcome was a clustered cardiometabolic risk (CCR) score, and the exposure was suburb-level SES. Potential mediators were domain-specific physical activities and sedentary behaviors. Multilevel linear regression models examined associations between SES and potential mediators (α) and between mediators and CCR (ß). Mediation was assessed using the joint-significance test. RESULTS: Higher SES was associated with a lower CCR score. Lower SES was associated with less frequent walking for transport, lower vigorous-intensity recreational physical activity, and higher TV time, which were associated with higher CCR scores. However, higher SES was associated with longer transport-related sitting time (all modes and in cars), which were associated with higher CCR scores. CONCLUSIONS: The SES-cardiometabolic risk relationship may be partially explained by walking for transport, vigorous-intensity recreational physical activity, and TV viewing. These findings, which require corroboration from prospective evidence and clarification of the roles of transport-related sitting and occupational physical activity, can inform initiatives addressing socioeconomic inequalities in cardiometabolic health.

Diurnal pattern of breaks in sedentary time and the physical function of older adults.

BACKGROUND: The association of breaks in sedentary time with outcomes of physical function can vary according to the time of day. We examined the association of the diurnal pattern of breaks in sedentary time with physical function outcomes in older adults. METHODS: A cross-sectional analysis was conducted among 115 older adults (≥60 years). The overall and time-specific breaks (morning: 06:00-12:00; afternoon: 12:00-18:00; evening: 18:00-24:00) in sedentary time were assessed using a triaxial accelerometer (Actigraph GT3X+). A break in sedentary time was defined as at least 1 min where the accelerometer registered ≥100 cpm following a sedentary period. Five physical function outcomes were assessed: handgrip strength (dynamometer), balance ability (single leg stance), gait speed (11-m walking), basic functional mobility (time up and go), and lower-limb strength (five times sit-to-stand). Generalized linear models were used to examine the associations of the overall and time-specific breaks in sedentary time with the physical function outcomes. RESULTS: Participants showed an average of 69.4 breaks in sedentary time during the day. Less frequent breaks in the evening (19.3) were found than that in the morning (24.3) and the afternoon (25.3) (p < 0.05). Breaks in sedentary time during the day were associated with less time on gait speed in older adults (exp (ß) = 0.92, 95% confidence interval [CI] 0.86-0.98; p < 0.01). Time-specific analysis showed that breaks in sedentary time were associated with less time on gait speed (exp (ß) = 0.94, 95% CI 0.91-0.97; p < 0.01), basic functional mobility (exp (ß) = 0.93, 95% CI 0.89-0.97; p < 0.01), and lower-limb strength (exp (ß) = 0.92, 95% CI 0.87-0.97; p < 0.01) in the evening only. CONCLUSION: A break in sedentary time, particularly during the evening, was associated with better lower extremity strength in older adults. Further strategies to interrupt sedentary time with frequent breaks, with an emphasis on evening hours, can be helpful to maintain and improve physical function in older adults.

Sedentary behaviour and sleep quality.

High-quality sleep is an important factor in sustaining health and improving well-being. Previous evidence has demonstrated the positive associations between increased physical activity and reduced sedentary behaviour (SB) with sleep quality. The substitutional relationships between SB, light-intensity physical activity (LPA), and moderate-to-vigorous physical activity (MVPA) need to be considered when examining how a particular behaviour may impact sleep quality. No studies, to our knowledge, have explored these substitutional relationships in middle-aged adulthood. Using an isotemporal substitution approach, this study examined the associations of replacing sedentary time with physical activity on sleep quality measures in a sample of middle-aged adults in Japan. Data from 683 adults aged 40-64 living in Japan were used. The average daily time spent in SB, LPA, and MVPA was objectively assessed by accelerometers. Two self-reported sleep quality measures were obtained using questionnaires, including rest by sleep and sleep quality. Multivariable linear regression models were used to assess the associations of SB, LPA, and MVPA with the sleep quality measures stratified by gender. We found that each 60 min unit of SB or LPA replaced with MVPA was favourably associated with rest by sleep among women (ß = 0.16, 95% CI 0.07, 0.28, p < 0.001; ß = 0.18, 95% CI 0.07, 0.32, p < 0.05, respectively). There were no significant associations between SB, LPA, and MVPA with sleep measures in men across all three models. These findings indicate that higher MVPA has a positive association with sleep quality in middle-aged women.

Physical therapist-delivered acceptance and commitment therapy and exercise for older outpatients with knee osteoarthritis: a pilot randomized controlled trial.

[Purpose] In this pilot study, we investigated the effectiveness of physical therapist-delivered acceptance and commitment therapy in older outpatients with knee osteoarthritis and chronic pain. [Participants and Methods] This single-center, open-label, parallel-group pilot randomized controlled trial included 30 patients assigned to the physical therapist-delivered acceptance and commitment therapy group (n=15) and the usual care physical therapy-only group (n=15). Both treatments were administered once a week for 8 weeks. Evaluation was performed 4 weeks before intervention, pre-intervention, post-intervention, and 4 weeks after intervention. The primary outcome was diagnosis of a physical disability, and secondary outcomes included psychological inflexibility, pain intensity, anxiety, depression, physical function, and objectively measured physical activity. [Results] Physical therapist-delivered acceptance and commitment therapy had a limited effect on physical disability, although we observed a favorable tendency. With regard to secondary outcomes, physical therapist-delivered acceptance and commitment therapy did not show significant effects. Notably, 15 patients withdrew from this study and 6 were diagnosed with coronavirus disease. [Conclusion] Physical therapist-delivered acceptance and commitment therapy did not appear to show significant effects in the present study. It is necessary to correct these issues in this study, and future studies are warranted to investigate the effects of this therapy.

The relationships between parents' and children's screen times on body mass index: a cross-sectional path analysis.

BACKGROUND: Understanding factors contributing to an individual reducing screen time is essential for promoting a healthy weight. Parents' behavior affects children by influencing their daily decision-making through modeling, rules or restrictions, social support, and co-participation. We examined how the direct and indirect effects of parents' and children's behaviors regarding screen time influenced body mass index (BMI) among Japanese elementary school children. METHODS: We included 283 Japanese children, one child per household, aged 6-12 years, who were randomly selected from resident registries of two cities. The questionnaires were completed by children and their mothers and fathers. Screen time and sociodemographic attributes, including sex, age, employment status, height, and weight, were assessed using a mail-based survey. Path analyses were conducted to determine associations among children's, fathers', and mothers' variables. It was hypothesized that after controlling for household income and children's sex and age, mothers' and fathers' screen time on weekdays and weekends would be related to children's weekdays and weekend screen time, respectively. In addition, we hypothesized that children's weekday and weekend screen time was related to children's BMI. RESULTS: Both fathers' and mothers' weekday screen times were associated with children's weekday and weekend screen times. BMI was affected by children's weekday screen time (0.117). The path coefficients for the indirect effects of mothers' and fathers' screen time on children's BMI through children's weekday screen time were 0.016 from the fathers' weekday screen time and 0.024 from the mothers' weekday screen time (GFI = .980, AGFI = .953, RMSEA = .030, AIC = 93.030). CONCLUSIONS: Both fathers' and mothers' weekday screen times indirectly affected children's BMI through children's weekday screen time among Japanese elementary school children. The strongest indirect effects could be seen by examining the paths of a mother's weekday screen time through children's screen time to BMI. Mothers who spend much time with their children are role models, and their behavior could affect the child's behavior. The findings imply that intervention strategies to reduce screen time in children should also focus on modeling the mothers' behavior.

Correlates of domain-specific sedentary behaviors and objectively assessed sedentary time among elementary school children.

Understanding the correlates of sedentary behavior among children is essential in developing effective interventions to reduce sitting time in this vulnerable population. This study aimed to identify correlates of domain-specific sedentary behaviors and objectively assessed sedentary time among a sample of children in Japan. Data from 343 children (aged 6-12 years) living in Japan were used. Domain-specific sedentary behaviors were assessed using a questionnaire. Total sedentary time was estimated using hip-worn accelerometers. Twenty-two potential correlates across five categories (parental characteristics, household indoor environment, residential neighborhood environment, school environment, and school neighborhood environment) were included. Multivariable linear regression models were used to identify correlates of domain-specific sedentary behaviors and objectively assessed sedentary time. Eight correlates were significantly associated with children's domain-specific sedentary behaviors: mother's and father's age, mother's educational level, having a video/DVD recorder/player, having a video console, having a TV one's own room, home's Walk Score®, and pedestrian/cycling safety. No significant associations were found between potential correlates and accelerometer-based total sedentary time. These findings highlight that strategies to reduce children's sedentary time should consider the context of these behaviors. For example, urban design attributes such as perceived pedestrian and cycling safety can be improved to reduce children's car sitting time.

Timing and intensity of physical activity and late sleeping habits among children in Japan.

Background: Little is known about what timing and intensity of physical activity (PA) are beneficial to preventing children's late sleeping habits. We investigated the association between timing and intensity of PA and late sleeping habits among Japanese children. Methods: The amount of PA on a weekday (light (>1.5 to <3.0 metabolic equivalents [METs]); moderate (3.0 to <6.0 METs); and vigorous (6.0 to <20.0 METs) was measured for the whole day, before school, during school, and after school, using accelerometers for population-based fourth-grade elementary school and eighth graders for 7 consecutive days between September and December 2018. Late sleeping habit (going to bed after 10 p.m. for fourth graders and after 11 p.m. for eighth graders) was assessed by questionnaires. The data of 229 fourth graders and 182 eighth graders were analyzed with Poisson regression adjusted for grade, gender, household income, body mass index (BMI), belonging to a sports club, wake-up time on weekdays, and PAs with different intensities. Results: Total PA was not associated with late sleeping habits. Light-intensity PA before school was protectively associated with late sleeping habits (prevalence ratio [PR]: 0.82, 95% confidence interval [CI]: 0.68, 0.99) while PA at school or after school was not. Conclusion: Light-intensity PA before school may enhance the earlier bedtime of children.

Differences in Accelerometer-Measured Physical Activity and Sedentary Behavior Between Middle-Aged Men and Women in Japan: A Compositional Data Analysis.

BACKGROUND: Differences in accelerometer-measured sedentary behavior and different physical activity (PA) intensities between men and women have been poorly described. The authors examined gender differences in time-use activity composition and total volume of PA. METHODS: A cross-sectional mail survey was conducted from 2013 to 2015 with a randomized sample of 6000 middle-aged (40-64 y) community-dwelling Japanese adults living in urban and regional cities. Participants wore Active style Pro HJA-350IT on their waist for 7 consecutive days. Gender differences in activity time use was examined using compositional data analysis to control for time spent in all activity measures. RESULTS: In total, 757 participants (303 men, 52.3 [7.1] y) with valid data were included in the analysis. Women spent on average 12.6% less time in sedentary behavior and 23.4% more time in light-intensity PA than men, whereas no significant difference was found for moderate to vigorous PA. Women accumulated a significantly greater volume of PA than men (17.8 vs 15.0 metabolic equivalent of task h/d). CONCLUSIONS: Japanese middle-aged women showed higher levels of PA than men because they spent more time in light-intensity PA. Given the health benefits of light-intensity PA, evaluating only moderate to vigorous PA may lead to an underestimation of women's participation in PA.

Associations between neighbourhood street connectivity and sedentary behaviours in Canadian adults: Findings from Alberta's Tomorrow Project.

Evidence suggests that neighbourhood street connectivity is positively associated with physical activity, yet few studies have estimated its associations with sedentary behaviour. We estimated the associations between space syntax derived street integration, a novel measure of street connectivity, and sedentary behaviours among Canadian adults. Data were sourced from a population-based study-Alberta's Tomorrow Project (n = 14,758). Items from the International Physical Activity Questionnaire captured sedentary behaviour, including sitting and motor vehicle travel time and walking. Street integration was measured within a 1600m radius of participants' homes. Covariate-adjusted linear regression models estimated the associations between street integration and sedentary behaviour. Street integration was significantly positively associated with daily minutes of sitting on week (b 6.44; 95CI 3.60, 9.29) and weekend (b 4.39; 95CI 1.81, 6.96) days, and for week and weekend days combined (b 5.86; 95CI 3.30, 8.41) and negatively associated with daily minutes of motor vehicle travel (b -3.72; 95CI -3.86, -1.55). These associations remained significant after further adjustment for daily walking participation and duration. More research is needed to understand the pathways by which street integration positively and or negatively affects sedentary behaviour.

Linear and non-linear associations of device-measured sedentary time with older adults' skeletal muscle mass.

BACKGROUND: Time spent sitting is associated adversely with health outcomes in older adults. Nevertheless, it is not clear how sedentary time may be related to appendicular skeletal muscle mass (ASM) - a key attribute of sarcopenia. This cross-sectional study examined associations of total sedentary time with ASM among community-dwelling older Japanese males and females. METHODS: Participants (n = 281, 74.3 ±â€¯5.2 yr) wore a tri-axial accelerometer for seven days. Body mass index-adjusted ASM (kg/BMI) was derived from bioimpedance measures. Multivariate linear and quadratic regression models examined the associations of ASM with total sedentary time, stratified by sex. Restricted cubic spline models were fitted to estimate non-linear associations. Isotemporal substitution (IS) models were used to estimate the impacts of replacing 30-minute of sedentary time with light physical activity (LPA) and moderate-to-vigorous physical activity (MVPA). RESULTS: After adjustment, total sedentary time had a significant linear and negative association with ASM among females (ß = -0.014; p = 0.023). For males, total sedentary time had a significant quadratic association (p = 0.020). Spline models indicated a reverse U-shaped association (p < 0.001) with total sedentary time over 9.3 h/day being associated with lower ASM. The IS models indicated that replacing 30 min/day of sedentary time with LPA would be positively and significantly associated with older females' ASM (ß = 0.007, p = 0.022). CONCLUSIONS: In older Japanese adults, higher volumes of time spent sedentary were associated with lower ASM. For males, only very high volumes of sedentary time appeared to be detrimental. These adverse relationships may in part be offset by more time spent in either LPA or MVPA.

Associations of public open space attributes with active and sedentary behaviors in dense urban areas: A systematic review of observational studies.

In the context of rapid urbanization, public open spaces in dense urban areas are critical built environment elements to support active lifestyles. Several reviews have explored the associations of public open space attributes with physically active and sedentary behavior. However, few reviews have included studies from Asia, and no studies have focused on dense urban areas. This systematic review analyzed 18 observational studies investigating associations between public open space attributes with physical activity and sedentary behavior in dense urban areas of East Asian countries, including Japan, Taiwan, China, and Hong Kong. We found that closer distance to and a greater number of public open spaces and features within them were positively associated with leisure-time physical activity. Places near water features and corridors within public open spaces were associated with more sedentary behavior. These findings inform landscape and urban design guidelines for (re)designing public open spaces to support active lifestyles in high dense urban areas.

Sedentary behavior is associated with reduced cardiovagal baroreflex sensitivity in healthy adults.

Sedentary behavior is an established risk factor for cardiovascular disease; however, it remains unclear whether sedentary behavior is associated with the deterioration of arterial blood pressure regulation. The purpose of this study was to determine the association between the time spent in sedentary behavior and cardiovagal baroreflex sensitivity (cBRS) in healthy adults. We investigated the cross-sectional relationship between sedentary time and cBRS in 179 adults aged 22-81 years. Sedentary time was objectively measured using a triaxial accelerometer. cBRS was evaluated by the transfer function gain of beat-by-beat changes in systolic blood pressure and the R-R interval during 5 min of spontaneous resting. Glycemic, lipidemic, and vascular risk factors were measured as potential covariates of cBRS and sedentary behavior. Men had a longer sedentary time and lower cBRS than women (p = 0.001). In a simple correlation analysis, older age was negatively associated with cBRS and positively associated with sedentary time, but sedentary time was not correlated with cBRS. However, after adjustment for age and sex, a longer sedentary time was associated with a lower cBRS. Multiple linear regression analysis showed that sedentary time was independently associated with lower cBRS with adjustment for covariates (ß = -0.325, p = 0.002). A significant association was also confirmed when the analysis was performed separately in the younger and older groups. This finding suggests that high sedentary behavior may have an adverse effect on arterial blood pressure regulation.

Psychological inflexibility and physical disability in older patients with chronic low back pain and knee pain.

Aim: This study examined the associations between psychological inflexibility (PI) and physical disability (PD) among older patients with chronic low back and knee pain. Methods: Pain avoidance and cognitive fusion were assessed in outpatients as components of PI and PD, and sociodemographic and pain-related variables were used as covariates. Hierarchical multiple linear regression was used. The covariates were first entered, followed by PI. Results: Age and pain intensity had significant positive associations with PD. After adding PI, only pain avoidance was significantly and positively associated with PD. Conclusion: Focusing on pain avoidance may be effective for physical disability when acceptance and commitment therapy is administered to older patients with chronic low back and knee pain.

Recently, psychological inflexibility (PI) as a psychological process of acceptance and commitment therapy (ACT) has attracted attention in the treatment of chronic pain. However, previous studies have not found a relationship between PI and physical disability (PD) in older patients with chronic lower limb pain. This study investigated whether PI is associated with PD in older patients with chronic low back and knee pain. PI, PD and sociodemographic and pain-related variables were measured using a questionnaire. The results showed that pain avoidance in PI was associated with PD, whereas cognitive fusion was not. Focusing on pain avoidance may be effective for physical disability when ACT is administered to older patients with chronic low back and knee pain.

Daily behavioral and sleep patterns are associated with aging-induced male-specific disorders in individuals with reduced renal function.

BACKGROUND: The development of aging-induced male-specific disorders is accelerated by impaired renal function. Although aging-induced male-specific disorders are clinically serious complications in individuals with reduced renal function, their practical management strategies remain obscure. The purpose of this cross-sectional study was to investigate the association between daily behavioral and sleep patterns and aging-induced male-specific disorders in individuals with reduced renal function. METHODS: Eighty men with glomerular filtration rate stage 2-4 (age, 67 ± 9 years), sedentary behavior and physical activity were assessed using a triaxial accelerometer. The mean sleep time was calculated from the sleep time during the accelerometer measurement. Sleep quality was assessed using the Pittsburgh Sleep Quality Index (PSQI). Aging-induced male-specific disorders were assessed using the Aging Males' Symptoms Questionnaire (AMS). RESULTS: A lower moderate to vigorous-intensity physical activity (MVPA) time and a higher PSQI score were independently associated with a higher AMS score. Moreover, when the participants were divided into four groups according to the median MVPA values and the PSQI score (more or less than 6 points), the AMS score was the highest in those with a lower MVPA time and a higher PSQI score. In the mediation analysis, the PSQI score did not mediate a correlation between the MVPA time and AMS score. MVPA time also did not mediate a correlation between the PSQI and AMS scores. CONCLUSIONS: Collectively, these findings suggest that increasing MVPA time and improving sleep quality may contribute to attenuating aging-induced male-specific disorders in individuals with reduced renal function.

Workplace neighbourhood built-environment attributes and sitting at work and for transport among Japanese desk-based workers.

Workplace settings-both internal and external-can influence how workers are physically active or sedentary. Although research has identified some indoor environmental attributes associated with sitting at work, few studies have examined associations of workplace neighbourhood built-environment attributes with workplace sitting time. We examined the cross-sectional associations of perceived and objective workplace neighbourhood built-environment attributes with sitting time at work and for transport among desk-based workers in Japan. Data were collected from a nationwide online survey. The Abbreviated Neighborhood Environment Walkability Scale (n = 2137) and Walk Score® (for a subsample of participants; n = 1163) were used to assess perceived and objective built-environment attributes of workplace neighbourhoods. Self-reported daily average sitting time at work, in cars and in public transport was measured using a Japanese validated questionnaire. Linear regression models estimated the associations of workplace neighbourhood built-environment attributes with sitting time. All perceived workplace neighbourhood built-environment attributes were positively correlated with Walk Score®. However, statistically significant associations with Walk Score® were found for sitting for transport but not for sitting at work. Workers who perceived their workplace neighbourhoods to be more walkable reported a longer time sitting at work and in public transport but a shorter sitting time in cars. Our findings suggest that walkable workplace neighbourhoods may discourage longer car use but have workplaces where workers spend a long time sitting at work. The latter finding further suggests that there may be missed opportunities for desk-based workers to reduce sitting time. Future workplace interventions to reduce sitting time may be developed, taking advantage of the opportunities to take time away from work in workplace neighbourhoods.

Sedentary Behavior and Happiness: The Mediation Effects of Social Capital.

BACKGROUND AND OBJECTIVES: This study aimed to examine the associations between time spent in 6 different domains of sedentary behavior and happiness and whether social capital mediated such associations among adults and older adults living in a rural area of Japan. RESEARCH DESIGN AND METHODS: Cross-sectional data from 3,357 participants (mean age: 60 ± 16 years) were used. 6 domains of sedentary behavior, happiness, and social capital were assessed using a self-report questionnaire. Age-stratified multivariable linear regression models adjusted for covariates were used to examine the associations between 6 domains of sedentary behavior and happiness. For relationships where the direct effect was significant, we tested the mediating effects of 2 social capital measures. RESULTS: Among both adults and older adults, more time spent viewing television was significantly associated with lower happiness scores, and more time spent engaging in other leisure activities was significantly associated with higher happiness scores. In addition, more time spent using cell phones and computers was significantly associated with lower happiness scores among the adults. Engaging in activities with neighbors significantly mediated the relationship between other leisure activities and happiness in the adults and older adults, and between television viewing and happiness in the older adults. DISCUSSION AND IMPLICATIONS: Our findings indicated that less television viewing and more mentally active sedentary behavior (e.g., talking with others and engaging in hobbies) were associated with greater happiness. One aspect of social capital, engaging in activities with neighbors, acts as a potential mediator for relationships between sedentary behavior and happiness.