This is the first study investigating relationships between urban, semi-urban and rural residence and older adults' walking and cycling. Furthermore, the relationship between the physical environment and walking and cycling behaviors and its possible moderators were explored.
35.9% of the participants reported to walk for transportation
daily, however urban participants were 43% and 32% more likely to walk for transportation daily compared to rural and semi-urban older adults, respectively. This is in concordance with findings in Australian [27
] and Flemish adults [28
] and might be explained by shorter distances to shops and services in urban areas. The latter is supported by the positive relationship between short distances to services and daily walking for transportation. However, no marked difference between urban, semi-urban and rural participants is observed in their ratings on the 'short distances to services' - measure (Table ). Possibly, urban, semi-urban and rural residents perceive distances differently. A higher number of neighborhood shops was also associated with more transportation walking in all subgroups except for rural ≥ 75 year olds. Hence, our findings support results from two previous studies on the application of the 'walkability' concept in older adults. Frank and colleagues [14
] found older adults living in objectively defined high-walkable neighborhoods to be twice as likely to have walked for transportation in the past 2 days than those in low-walkable neighborhoods. In another US study older adults living in objectively defined high-walkable neighborhoods accumulated 30 minutes/week more transport activity (walking and cycling) compared with those living in low-walkable neighborhoods [15
An important destination to walk to and from appears to be public transit. Greater satisfaction with public transportation was associated with more walking for transportation. In addition, a higher percentage of public transportation subscriptions was related to more transportation walking in urban subgroups. Having access to public transit might enable older adults to reach destinations situated further away by a shortened walk to a bus or rail stop. Investigating public transit characteristics in British older adults, Su and colleagues [12
] reported less time between bus services and higher bus stops density to be associated with more walking for shopping purposes.
A higher score on the 'Elderly Feelings of Unsafety scale' was associated with lower prevalences of daily walking for transportation. This is in accordance with a previous study which reported perceived neighborhood problems (e.g. vandalism) to be related to less transportation walking in US older adults [29
]. However in another study in US older adults, Shigematsu and colleagues reported no relationship for perceived safety from crime. These discrepancies in findings might be explained by the questionnaires used to asses perceptions of safety [30
]. Presence of street lighting, a factor possibly influencing feelings of unsafety, was associated with more daily walking for transportation in females but not in males. This relationship was also somewhat stronger in the oldest age group.
No relationship for presence of crossings was found in urban residents, whereas a positive relationship was found in semi-urban residents and a negative relationship in rural residents. A possible explanation for the importance of crossings in semi-urban areas is the location of busy arterial roads, which necessitates the presence of crossings in order to cross them safely, in these areas. The negative relationship between presence of crossings and walking for transportation observed in rural areas was unexpected and possible reasons are unclear.
In a Dutch study [13
] the objectively measured absence of high ramps, presence of benches and trees was unrelated to a street's use for transportation walking. Similarly, the perceived absence of high ramps, presence of benches and satisfaction with greenery was unrelated to daily walking for transportation in the present study.
Unexpected negative relationships for traffic safety, presence of public toilets, quality of sidewalks and absence of noise and decay were observed. A possible explanation is the cross-sectional nature of this study as participants who walk daily encounter and suffer from these problems more frequently and might report them more easily. Furthermore, destinations (e.g. shops, post offices...) are often located in busy shopping streets which might explain that more walking for transportation was associated with lower perceptions of absence of decay and noise.
Almost one quarter of the participants reported to cycle for transportation
daily. Urban residents were less likely to cycle for transportation daily compared to semi-urban residents. No differences in likelihood of daily cycling were found for rural versus semi-urban and rural versus urban residents. These findings suggest that when distances are longer older adults rather cycle instead of walk, which seems obvious as greater distances are easier and faster covered cycling compared to walking. However, in rural areas distances might be too large in order to bridge them by cycling. Perceived short distances to services was indeed related to daily cycling for transportation, but the relationship was stronger in females compared to males. Possibly, lower physical fitness levels in females compared to males [31
] and consequently more difficulties in overcoming greater distances explain these gender discrepancies. Number of shops in the neighborhood was also related to a higher likelihood of daily cycling for transportation.
Higher satisfaction with public transportation was related to more cycling for transportation. Again, public transportation might enable older adults to bridge larger distances compared to cycling alone. Investigating the relationship between types of public transportation and the transport mode to reach them, cycling was found to be more common to faster and high quality types of public transportation (e.g. trains) compared to slower and lower quality types of public transportation (e.g. local buses) [32
]. Walking was reported to be most common when the railway station is situated within 1.5 km from the participants' home. Cycling to the station was most popular when located between 1.5 and 3.5 km away [33
]. In the present study, the relationship between percentage of public transportation subscriptions did not reach significance in any of the subgroups, although the ORs were large, especially in rural areas. If these trends are confirmed in future studies, providing a well-accessible public transport network seems a good strategy to promote cycling for transportation. More studies on relationships between characteristics of public transit and older adults' active transportation are needed.
Feelings of unsafety were related to a decreased likelihood of daily cycling for transportation in females but not in males. Related to this, presence of street lighting increased the likelihood of daily cycling in < 75 years old females and rural females but not in other subgroups. Apparently, with regard to cycling for transportation women are more susceptible to feelings of unsafey. Providing adequate street lighting might be one solution to overcome this problem.
Traffic safety was negatively related to daily cycling for transportation which might again be explained by the cross-sectional nature of this study. Older adults who cycle daily might experience traffic concerns frequently and therefore report them more easily.
The presence of public toilets, benches, crossings, satisfaction with greenery was found to be unrelated to cycling for transportation. Absence of decay and noise were not related to cycling for transportation in most subgroups. However for both, a negative relationship was found in urban < 75 years old males and a positive relationship was observed in rural < 75 years old females for absence of noise. The reasons for these inconsistent findings between subgroups are unclear.
About half of the participants reported to walk or cycle for recreation
weekly. Walking and cycling for recreation was unrelated to area of residence. This is in line with findings for recreational walking in Australian adults [27
]. One might expect recreational walking and cycling to be more common in the green and quiet rural areas. However, results of the present study suggest that urban older adults walk or cycle for recreation in city centers and shopping streets. This is supported by the positive relationships for number of shops and short distances to services. However, Van Dyck and colleagues [28
] reported more recreational walking but less cycling in urban compared to rural neighborhoods in Flemish adults. These opposite relationships might have resulted in no relationship for the combination of recreational walking and cycling in the present study.
Feelings of unsafety were associated with lower prevalences of weekly walking/cycling for recreation. This finding supports results from a longitudinal study in the US which showed perceived general safety to be related to less decline in older adults' recreational walking at 12 months follow-up [34
]. However, perceived general walking safety was unrelated to older adults' recreational walking in two other US studies [35
]. These three studies used a general safety measure whereas in the present study it specifically focused on safety from crime. Furthermore, it was shown in the present study that this relationship between safety from crime and recreational walking/cycling holds true for both males and females, < 75 year olds and ≥ 75 years old and in urban, semi-urban as well as rural areas.
In summary, no clear patterns emerged for environmental factors other than access to destinations and feeling of unsafety. Possibly, the presence of one 'favorable' environmental factor might not be sufficient to influence walking or cycling behaviors. This is supported by the strong relationship between walking and cycling for transportation and area of residence, which is characterized by a specific combination of environmental factors. Sallis and colleagues [37
] reported that at least 4 favorable environmental factors needed to be present to find a significant relationship with adults' PA.
A first strength of this study is the large sample size, which enabled us to investigate interaction effects and create subgroups. Secondly, the sample included urban, semi-urban and rural residents while previous studies primarily focused on urban residents. Lastly, the focus on specific PA domains and especially on cycling behaviors, which had not been studied before in this population, certainly adds to the value of this study. However, aggregating walking and cycling for recreation might have obscured relationships with these behaviors. A second limitation is the absence of information on the psychometrics of PA measures used in the present study. Furthermore, only frequency of walking and cycling was assessed and walking and cycling for transportation were expressed as daily habits while walking/cycling for recreation was assessed as a weekly habit. Consequently, caution is needed when comparing results for transportation and recreational walking and cycling. Furthermore, given the relatively high prevalences of walking and cycling in our sample, our findings might not be completely applicable to other contexts. Thirdly, some potentially important environmental factors were not assessed (e.g. presence of cycling facilities). A last limitation is the cross-sectional design which prohibits us from drawing conclusions about causality.