Insufficient physical activity in Nepal typical of a low-income nation
The prevalence of LPA in our peri-urban study population is consistent with the findings of smaller studies in urban Nepal [22, 23] but less compared to studies in the neighboring capital city of Kathmandu (82%) . However, this prevalence far exceeds the national average (5.5% [95% CI 3.4–7.7]) reported by the WHO STEPs survey using GPAQ  or the 8% estimated by the World Health Survey using IPAQ .
A comparison of Nepal to other countries clearly demonstrates worldwide variations in the prevalence of physical inactivity [2, 9]. Generally, the prevalence of physical activity associates positively with the national economy, ranging from around 5% in Bangladesh (another low-income nation) to around 15% in middle-income countries such as India and Viet Nam and greater prevalence in high-income countries such as Australia (38%), the United States of America (40%) and the United Kingdom (63%) [9, 38]. In addition, studies from other Asian HDSSs, including Vietnam (e.g., 13% in the rural Chililab HDSS and 58% in the urban Filabavi HDSS) show rural–urban disparities in physical inactivity levels . Similarly, the current burden of physical inactivity in Nepal clusters around urban and urbanizing populations .
Contrasting physical activity in different domains
Despite rapidly declining levels of physical activity worldwide , emerging evidence suggests that different domains, particularly leisure time, play an important role in CHD reduction [42, 43]. Active transportation methods (e.g., cycling and walking) associate with decreased levels of all-cause mortality . Further, some studies have explored the interrelationship between different domains of physical activity. For example, we found a positive correlation between occupational physical activity and LTPA, results that concur with a study in the United States . However, our study did not investigate other occupation-related factors that inversely associate with leisure activity (e.g., job strain, working hours and overtime) .
Our finding of less physical activity during leisure time concurs with results from other urban  and HDSS studies in Asia . In the context of traditionally urban Nepal, leisure-time activities (e.g., sports and exercise, including jogging) associate more frequently with youth or modern culture. Most Nepalese spend their leisure time watching television, socializing, gossiping or playing cards. Moreover, physical activity levels in Nepal vary seasonally and physiologically [46, 47].
Like many low-income countries, most physical activity in Nepal associates with work or occupation-related activities . In contrast, high-income countries exhibit lower work-related physical activity, thus encouraging physical activities during transportation (e.g., cycling in Denmark) and leisure (e.g., Sweden, Canada, England and Spain) .
Sociodemographic variations in physical activity levels
In the present study, women did more household chores than men, reflecting an almost universal pattern in the traditionally patriarchal society in Nepal and other Asian countries [39, 45]. Nonetheless, our female respondents were more likely to have low overall physical activity. Male sex is a positive determinant of greater physical activity in children aged 4–9 years but not thereafter . Further, risk reduction for CHD through regular physical activity is more pronounced in women than men (40% and 30%, respectively) . In terms of age, the inverse relationship between age and physical activity is an almost global phenomenon, with some notable exceptions (i.e., New Zealand, Australia, China and some East Asian countries) [20, 48, 49]. Importantly, physical activity reduces cardiovascular risk even in old age .
In the present study, ethnic minorities showed less physical inactivity, a result that concurs with other findings [48, 50, 51] including those by studies that conducted objective measurements in children of different ethnic background . Earlier studies attribute this disparity to fewer facilities for outdoor physical activity and a greater number of fast-food outlets in ethnic neighborhoods . This discrepancy persists even after adjusting for possible sociodemographic variables, health-related factors and health-belief variations . Further, physical activity preference differs according to ethnicity . Indeed, protection against CVD through physical activity is apparent across not only gender and age but also ethnicity .
Studies in developed countries report that education level correlates positively with physical activity [19, 48], but our results revealed a step-wise inverse relationship. Other Asian HDSSs report similar findings , suggesting the probability of a contrasting trend of physical activity across the educational strata in low- and high-income countries. Our finding of highest TPA but lowest LTPA among agricultural workers concurs with findings from India , China , Finland  and elsewhere .
Lower level of physical activity in people with cardiovascular risk factors
Our respondents showed a similar prevalence of smoking, and current alcohol consumption was lower than the national average . The prevalence of hypertension was similar to the national percentage . Obesity was double the national average  and similar to that in nearby urban Kathmandu , hinting that the effect of urbanization is spilling from the urban area into nearby rural communities, a phenomenon already demonstrated in India . In our study, the probability of inadequate physical activity was higher among individuals with diagnosed hypertension, diabetes mellitus or overweight/obesity. Due to the cross-sectional nature of our study, we cannot comment on physical inactivity as a cause or consequence of these cardiometabolic conditions. Nonetheless, earlier studies report decreased levels of physical activity following diagnosis with a chronic condition such as diabetes  or hypertension , mainly due to co-morbidities (e.g., arthritis) or social demands . This phenomenon has been observed worldwide, particularly in low-income countries . In addition, the relationship between overweight/obesity and physical inactivity can create a vicious cycle where in various psychosocial factors (e.g., fear of being teased or bullied, fear of negative judgments and lack of social or peer support) limit physical activity in overweight/obese people in .
Physical activity as an outcome of urbanization and changing lifestyle in Nepal
In our study population, high prevalence of physical inactivity reflects a side effect of development and urbanization in a low-income country like Nepal. For example, farming, which is a physically demanding occupation, decreased from 94% to 65% during the last 30 years . This reduction corresponds with a similar decrease (from 60% to 33%) in agriculture’s share of GDP  and an escalating utilization of local land for new construction . Further, although most farm equipment in Nepal is still powered by animals (41%) or humans (36%), mechanized equipment is gradually increasing (23%) . Increased availability of motorized vehicles  and improved water supplies  have drastically decreased tradesmen’s demand for business-related mobility and women’s need to walk long distances for basic requirements (e.g., water). Modern technical gadgets that promote sedentary behavior frequently replace leisure activities (e.g., games and cultural rituals) , especially in the children and young adults.
Our results show that occupational activities comprise a major portion of total physical activity in JD-HDSS, raising concern for public health. Economic growth increases urbanization and reduces physical activity [1, 71]. Earlier trends for physical activity transition  in western countries [73, 74] and, more recently, in rapidly changing economies (e.g., China)  suggest that sedentary jobs will increase in Nepal. Lacking attempts to counteract this inevitable development by increasing physical activity in other domains (i.e., transport and leisure), overall physical activity likely will decline. Therefore, Nepal should not delay initiating interventions that improve physical activity through community-based strategies that incorporate informational, behavioral, social, policy and environmental approaches [76–78].
Lack of physical activity-friendly environment in urban Nepal
Although built environments influence physical activity [79, 80], our study did not explore this issue. Nepal’s roads are generally considered the most dangerous in the world for pedestrians [81–83], largely due to nonexistent pavement or cycling lanes, muddy and dilapidated roads, escalating traffic and congestion, negligent drivers who violate traffic rules, air pollution from dust and vehicular emissions and encroachment by street vendors. Many of these factors, including walkability , have a significant association with physical activity . Further, Nepal’s urbanization is completely unplanned and settlements are haphazard. Parks and playgrounds, which associate positively with leisure-time physical activity in other settings [86, 87] are uncommon in urban areas of Nepal. When governments do not prioritize aesthetic appeal and green space, people are less likely to engage in physical activity, especially during commuting and leisure time . Contextually, the built environment has a complex relationship with psychosocial and sociocultural aspects of physical activity . To identify targets for possible interventions to increase physical activity, future research should address these areas.
Strengths and limitations of the study
Our study is the first detailed report on physical activity in an urbanizing population of Nepal. Earlier studies on the epidemiology of physical activity were conducted in high-income countries , but our timely study bridges this knowledge gap in a low-income setting. Similar to other HDSS studies , JD-HDSS provides a good platform for understanding the patterns of physical activity patterns in a peri-urban population. In addition, the longitudinal nature of an HDSS offers the advantage of systematic follow-up to examine trends and the effectiveness of interventions . Moreover, our analysis demonstrates and reinforces the importance of ethnicity in cardiometabolic risk assessment [90–92]. However, our study did not explore in detail the social and environmental correlates of physical activity.
We adapted international data collection tools (including self-reported physical activity) to the local Nepali context [12, 34]. Although self-reported questionnaires provide inadequate validity compared to objectively-measured physical activity tools such as accelerometers [15, 93–95], such tools were too sophisticated, logistically impractical and expensive for successful use in our study setting. Additionally, objective tools carry their own limitations .
Despite the application of Kish technique during the selection of respondents at the household level, we previously reported unintentional oversampling of women . We addressed this deficit by stratifying our results according to gender. Further, we excluded 137 of 777 respondents during analysis due to incomplete information regarding blood pressure or anthropometric measurements. Although including only respondents with complete information (i.e., three readings for each measurement) improved the validity of the study, the process also resulted in an 18% reduction in the study sample.