The health conditions of the elderly are a widespread concern worldwide, and studies focusing on the improvement of health status by increasing the time spent performing a physical activity on a middle or large scale has attracted the attention of researchers in China and abroad. Creating an environment conducive to physical activity can improve the lifestyle behaviour of the elderly, reduce their huge demand for healthcare, enable them to maintain good health for a longer time, and delay or avoid disability, thus reducing the medical costs of families and society. Therefore, this study mainly explored the relationship between the urban layout of sports facilities in the 500 m buffer zone and the time spent performing physical activities and achieving the recommended level of physical activity for the elderly. Our results provide theoretical support for healthy urban planning and the transformation of the urban layout of sports facilities to promote elderly MVPA to improve health, and provide decision-making auxiliary information for achieving the strategic development goal of a ‘Healthy China 2030’.
This study found that compared with elderly individuals with no access to sports facilities in the 500-m buffer zone, elderly individuals with access to 6–7 sports facilities spend more time engaged in physical activities in China. In buffer zones with 1–3, 4–5, or > 8 sports facilities, the time spent on physical activity only increased. The results showed that there are 6–7 sports facilities in the buffer zone, which is more conducive to physical activity of the elderly. The results of this study are consistent with those of previous studies. Eriksson et al. conducted a cross-sectional survey of 32 communities and found that after controlling for sex, income, age, and other factors, participants with more than 4 sports facilities in the 1000-m buffer zone spent 5.4 min more performing physical activity per day than those with no sports facilities available[17]. In addition, after adjusting for potential confounding factors, participants living in the higher tertile place of source density were more likely to report performing physical activity weekly compared to those living in the lowest tertile regions with resource density[18]. Some studies have also found that there is a significant correlation between the objectively assessed sports facility density and the self-reported exercise frequency in the circular buffer zone[19]. However, a study in the United States found no relationship between the density of sports facilities in the 805-m (0.5 mile) buffer zone and self-reported physical activity[20]. This study measured the availability of sports facilities at the provincial level, and the concentration of measurement areas may explain the lack of association. Compared with previous studies, this study used objective measurement to assess the availability of sports facilities and physical activity of the elderly in order to eliminate bias associated with self-reporting; thus, the research results are more reliable. After controlling for confounding factors, there was still a significant relationship between the large adherence to habitual physical activity practices of the elderly and the availability of 6–7 sports facilities. Therefore, it is very important to create a suitable number of sports facilities to encourage the elderly to engage in physical activities more frequently, and it is helpful for policymakers to formulate policies for the construction of communities promoting physical activity in Nanjing and other cities with similar populations and social and economic conditions. Recent studies have shown that age may change the association between constructed environments and the levels of physical activity[21]. This study found that the relationship between the availability of sports facilities and the amount of physical activity was significantly higher in the elderly aged 60–65 years than in the other three groups (P < 0.01); this showed that the amount of physical activity in the elderly gradually decreased with increasing age. This may be due to the decreased muscle strength and muscle mass in elderly individuals with increasing age; muscle strength will decrease by 12–15% every 10 years after the age of 50 years[22]. Therefore, the elderly often feel powerless, which leads to their unwillingness to engage in moderate to high intensity physical activity. There is also a positive association between outdoor physical activity and the availability of sports facilities to individuals aged > 80 years, according to this study. Although the mobility of the elderly decreases, the availability of sports facilities in the buffer zone can still promote outdoor activities[23]. The study also found that the duration of outdoor physical activities in male elderly individuals was significantly longer than that in females (P < 0.05). The results show that there are sex differences with regard to the impact of the urban layout of sports facilities in the buffer zone on the outdoor physical activities of the elderly. This may be due to the limitations of the female elderly who engage in assisting their children and take care of their children and perform other family tasks, as well as maintain social contact. They have fewer opportunities for outdoor activities, resulting in less outdoor physical activities than the male elderly. In addition, the study found that community type is also an important factor affecting the relationship between the outdoor physical activity and the availability of sports facilities. Compared with the traditional community, the amount of moderate and large outdoor physical activity performed by the elderly in marginal community is significantly higher, and the outdoor medium and large physical activity performed by the elderly in the comprehensive community and unit community shows an increasing trend. Through field investigation, it was found that the total number of sports facilities is in the decreasing order of marginal community (60), unit community (43), comprehensive community (37.5), and the traditional community (6). This shows that the elderly in marginal communities are more likely to obtain physical activity resources than those in a traditional community, which means that the elderly in marginal communities have more opportunities to carry out outdoor physical activities, allowing them to achieve higher levels of physical activity. It is also possible that most of the elderly in marginal communities migrate from rural areas, where they had to perform more physical labour such as planting vegetables or flowers, and assist the community in different roles, such as managing the parking. Moreover, the marginal communities are situated far from traffic stations (Such as bus stations, metro stations, public transportation), which increases their travel time and improves their physical activity outdoors. In addition, the elderly in marginal communities have good neighbourhood relations and have close contact with each other. They are also willing to chat, walk, and engage in recreational activities in public places. However, because of the high density of buildings and the conflict between people and land in the traditional community, there is a serious shortage of buildings and equipment for the elderly; therefore, the level of physical activity of the elderly is low. This study found that monthly income, education level, living style, chronic diseases, and self-rated health factors did not change the relationship between outdoor physical activity and the availability of sports facilities.
A Swedish study comprising 2037 adults found that adults with access to more than 4 sports facilities within 1000 m from their homes were 69% more likely to complete the recommended amount of physical activity (OR = 1.69, 95% CI: 1.39–2.05)[17]. However, Halonen et al. suggested that adults living near more than three sports facilities did not show an association with the completion of the recommended amount of physical activity[24]. This study found that the elderly with access to 6–7 or > 8 sports facilities in the 500-m buffer zone were more likely to reach the recommended value of physical activity than were those without access to sports facilities, and their compliance rate was increased by 120% and 100%, respectively. However, when there are 1–3 or 4–5 sports facilities in the buffer zone, the physical activity standard reaching rate of the elderly only increases. After controlling the combined factors of sex, age, average monthly income, highest education, self-assessment of health, community type, chronic disease, and living style, the physical activity standard rate of the elderly with 6–7 sports facilities in the buffer zone can still be increased by 118%. The results show that an increase in the availability of sports facilities can effectively improve the standard rate of physical activity of the elderly. When 6–7 sports facilities are available, it would be beneficial to improve the standard rate of physical activity of the elderly, which would provide a threshold to increase the availability of sports facilities. When the threshold is exceeded, the effect on improving the physical activity standard rate of the elderly will decrease. The reason for the inconsistency between the previous research results and the results of this study may be the difference in the research objects; the elderly exhibit greater viscosity, limited movement range, and most of the elderly remain in the community. Therefore, the availability of sports facilities in the 500-m buffer zone is more meaningful in order for the elderly to achieve the recommended level of physical activity. However, adults are busy with work and often travel between work and residential areas, which may lead to differences in the results between the availability of sports facilities and physical activity. The impact of the availability of sports facilities on the compliance rate of the elderly is as follows: 1) easy access to sports facilities reduces the psychological and physical barriers of exercise; the distance from home is a common obstacle for the elderly to exercise, and reducing commuting time can increase the motivation of the elderly to use facilities more frequently; 2) the increase of the availability of nearby facilities is conducive to the elderly to find a suitable exercise method; 3) the existence of sports facilities can be used as visual stimulation for all elderly people, so as to improve the overall level of physical activity in the community as a whole, rather than just exercise in the facilities[25–27].
This study found that age is an important factor affecting the rate of reaching the recommended levels of physical activity in the elderly. The probability of obtaining the recommended level of physical activity for a 60–65-year-old is 40% higher than that of a 66–70-year-old, 55% higher than that of a 71-75-year-old, and 74% higher than that of a 76–80-year-old. It shows that the rate of reaching the standard of physical activity gradually decreases with increasing age, which seriously threatens their health. Therefore, in order to improve the physical activity levels of the elderly, in addition to improving the availability of sports facilities, the intrinsic motivation of the elderly to exercise should not be ignored, and the attractiveness of improving outdoor exercise environment should be improved, so as to reduce the decline of physical activity caused by aging and improve their health level.
The study also found that different types of communities also affected the relationship between the availability of sports facilities and the recommended level of physical activity. The physical activity compliance rate of the elderly in marginal communities was significantly higher than that in traditional communities, which increased by 200%. The elderly in marginal communities have more facilities to use, convenient access to resources, and have more opportunities to engage in physical activities, which improves the compliance rate and promotes the level of health of the elderly. Some studies also show that the leisure time of the elderly can be increased by 1.3 minutes and the duration of physical activity of the middle and large usually can be increased by 1.4 minutes for each additional sports facility[28]. This study found that an increase in the availability of sports facilities can significantly increase outdoor physical activity and the exercise motivation of the elderly. This study found that the average monthly income, education level, lifestyle, chronic diseases, and self-rated health factors did not change the relationship between the recommended amount of physical activity completed by the elderly and the availability of sports facilities (P > 0.05).
Although acceleration measurement of physical activity can overcome the shortcomings of self-reporting, there are still some limitations in this study. Because this was a cross-sectional study, the causal relationship between factors could not be determined. In addition, there may have been a combination of factors that were not controlled for in this study (i.e. residual mixing may have occurred). Future research will continue to explore the relationship between the construction of sports facilities, accessibility and physical activity of the elderly, and the impact of perceived facility quality, environmental quality, and safety on physical activity of the elderly.