Guidance about age‐friendly outdoor exercise equipment and associated strategies to maximise usability for older people

Abstract Outdoor exercise equipment has become popular as important environmental infrastructure to provide opportunities for physical activity and social connectedness in public settings. With higher sedentary behaviour and physical inactivity reported among older people, infrastructure changes and safe environments that promote older peoples’ health and mobility are required. Due to ageing‐related functional decline and health conditions associated with ageing, older adults may have special physical needs that require careful consideration when choosing outdoor equipment. However, limited information is available regarding the suitability of the types of exercise equipment for older people. This commentary provides further information on the type of equipment available, its functionality and suitability for older age populations and key considerations for the decision‐maker involved in selecting, installing and supporting community use of outdoor exercise equipment. Recommendations on what is required to maximise usability from a system or organisational‐based approach using research evidence is also discussed. Older people are more susceptible to the negative influences of their local environment and outdoor neighbourhood conditions. Consequently, the age‐friendliness and suitability of the outdoor exercise equipment characteristics, location and settings may facilitate older adults’ engagement in physical and social activities.

physical needs that require careful consideration when choosing outdoor equipment.
However, limited information is available regarding the suitability of the types of exercise equipment for older people. This commentary provides further information on the type of equipment available, its functionality and suitability for older age populations and key considerations for the decision-maker involved in selecting, installing and supporting community use of outdoor exercise equipment. Recommendations on what is required to maximise usability from a system or organisational-based approach using research evidence is also discussed. Older people are more susceptible to the negative influences of their local environment and outdoor neighbourhood conditions. Consequently, the age-friendliness and suitability of the outdoor exercise equipment characteristics, location and settings may facilitate older adults' engagement in physical and social activities.

K E Y W O R D S
ageing, built environment, local government, older people, physical activity, exercise and frameworks to promote sports and recreation in outdoor spaces is important to enable residents and visitors with diverse abilities to be physically active.
The world population is ageing. In Australia, the number of older people is projected to increase from approximately 3.8 million in 2017 to 8.8 million in 2057 (22% of the population). 4 Given the projected increase in the number of older people in coming years, there will be increased demand on state and local governments to strategically focus on positive ageing and inclusiveness through the creation of age-friendly environments and health promotion interventions.
Being active outdoors is beneficial for mental, physical and social health across the lifespan. 5,6 In older age in particular, therapeutic landscape (nature and greenery) can positively impact on physical, mental and social health, in which experiences of nature provoke feelings of renewal, restoration and spiritual connectedness. 7 With higher sedentary behaviour and physical inactivity reported among older people, local governments are well positioned to make infrastructure changes that promote older peoples' health and mobility by creating outdoor spaces for older people to engage in physical activity.
Outdoor exercise equipment (often referred to as outdoor fitness equipment, outdoor gym, fitness zone, seniors playground and seniors exercise park) has become popular as an important environmental infrastructure to provide opportunities for physical activity and social connectedness in public settings at no cost. [8][9][10] The concept of promoting healthy living behaviour through the installation of outdoor exercise equipment has demonstrated some promise in the facilitation and improvement of physical activity patterns and also as a cost-effective investment for increased park utilisation and park-based physical activity. 8,11 Due to ageing-related functional decline and health conditions associated with ageing, older adults may have special physical needs that require careful consideration when choosing outdoor equipment. Older people are more susceptible to the negative influences of their local environment and outdoor neighbourhood conditions. Consequently, the age-friendliness and suitability of outdoor exercise equipment characteristics, its location and settings are important to facilitate older adults' engagement in physical and social activities.
With the increasing popularity of outdoor exercise equipment, there are a wide range of exercise equipment options available, yet little information on how to choose the right equipment to suit the targeted primary end-user group. 12 Specifically, limited information is available regarding the suitability of these types of exercise equipment for older people. Whilst outdoor exercise equipment generally targets adults, their nonspecific nature means that their suitability for older people might be questionable. This commentary aims to provide further information on the types of equipment available, its functionality and suitability for older age populations, and key considerations for the decision-maker involved in selecting, installing and supporting community use of this equipment. This commentary also provides recommendations on what is required to maximise usability from a system or organisational-based approach using research evidence.

| WHAT TO CON S IDER WHEN CHOOS ING OUTDOOR E XERCIS E EQU IPMENT FOR OLDER PEOPLE
There are several factors that need to be considered for suitable equipment selection and purchase. These include: the type of equipment, its functionality and limitations, the targeted demographic, the primary end-users' physical needs and the physical built environment. Other factors to increase participation and usage are also discussed. A summary of recommended considerations check list is provided in Table 1.

| Types of common outdoor equipment, targeted users and safety considerations
A summary of the type of equipment, targeted users and associated safety considerations is provided in Table 2. Outdoor equipment can be classified as follows: • Dynamic aerobic/cardio machine -includes circular/elliptical motion, aiming to challenge the cardiorespiratory system. Examples of cardio outdoor equipment include the skywalk, bicycle, ski walker, cross trainer ( Figure 1A).
• Dynamic resistance gym-based machine -mimics the conventional indoor gym equipment where it targets strengthening of the skeletal muscles. This equipment includes pushing or pulling against resistance (body weight or equipment weight as set by the manufacturer). Examples include leg press, pull/push up, shoulder/chest press ( Figure 1B).
• Other static gym-based equipment -includes pull or push up bars and benches (eg, sit up) that require the user to work against his/ her body weight ( Figure 1C,D) • Mobility and stretching equipment includes equipment stations that target flexibility and range of motion and requires movement/sliding of body parts -(shoulder/arm arch, core twister) • Seniors Exercise Park -includes multiple equipment stations (multimodal exercise equipment) that target mobility, functional movement, unstable and uneven balance surfaces ( Figure 1E).
• Other type of equipment may include walking beams ( Figure 1F) and elevated jump box/bars that target agility ( Figure 1G).
The above items of exercise equipment have some limitations.
Most equipment comes with manufacturer restrictions in terms of movement, minimum age restrictions, weight and shape/size. Adjustments for individual ability or body dimensions (height, body limbs length) are often not possible. For example, the dynamic gymbased machines do not allow adjustment of parts (eg, seat), they also require users to have the strength to push/pull against the weight of the equipment. Moreover, adjustment to various resistance levels might be limited, hence, individualised exercise regression or progression (decrease or increase the demand of an exercise or movement through minor changes such as increase/decrease weight/ resistance) cannot be made. If users do not possess the level of strength required to move the equipment, they will be unable to use it or they will use it incorrectly (poor technique). Similarly, the aerobic machines often require minimum effort for operation with no ability to change. Consequently, the frequent lack of adjustable resistance or progressively adaptable elements do not allow for appropriate and sufficient muscle stimulus to suit different individuals. 13 Outdoor equipment that incorporates stations/equipment pieces that mimic day-to-day movements and activities (eg, sit to stand, stair climb, reaching) might be of greater benefit for older people due to its emphasis on functional strength and joint range of movement required for daily functioning and independence. 14 Individualising exercises to suit various abilities for older people might be possible using such equipment. An example of individualisation of an exercise program with various levels of progression to suit older people can be found using the Seniors Exercise Park equipment. 15,16 However, it is important to note that for older people who lack the knowledge and or the experience in how to exercise, providing a professional exercise session/program with an exercise instructor might be required, at least in early stages of acclimatisation for safe and correct use of the exercise equipment. This is also important as inappropriate usage behaviour (operation of outdoor exercise equipment not according to manufacture instructions) might pose potential safety risks. 17 From a safety perspective, another important aspect to consider with outdoor exercise equipment options that aim to improve balance performance (eg, balance platform/beam, unstable surfaces) is the inclusion of safety rails (as provided in some equipment kits such as the Seniors Exercise Park equipment) and the potential need for professional advice. While using this type of equipment is likely to be safe for healthy older people to exercise on, older people with balance or mobility impairments may require health professional advice and supervision. Appropriate signage, safety disclaimer messages and promotion of this information (through avenues such as local council information) disseminated to areas around where these type of parks are located are required to ensure that use is limited to those who can safely use the park equipment.

| The recommended type and duration of physical activity for older people
The recommended physical activity guidelines for older people advise older people to engage in at least 30 minutes of physical activity daily that incorporates moderate fitness activities (for cardiorespiratory health), strength activities (for muscle and bone health), flexibility activities (to maintain joint range of motion) and  Step height higher than the accepted standard height (22.5 cm) will limit usability balance activities (to reduce falls). 18

| The physical built environmentlocation and settings
The how it can impact on who can access it. For example, installation of outdoor equipment along tracks will require users to have the physical ability to access it by foot, therefore, older people who are unable to walk unaided or for long distances are unlikely to be able to access, and therefore use, the equipment. To increase older peoples' participation, easy access, close by amenities and community hubs (community centre, senior groups) are important to consider. 24

| Surrounding surface and pedestrian infrastructure
The

| Weather elements
Older people in particular are vulnerable to extreme weather. 26,27 They are more sensitive to changes in the environment, which is a by-product of a lower physiological reserve capacity, slower metabolism, and a more slowly responding immune system. 26 This makes their body less able to tolerate stress such as posed by the environment (extreme hot/cold weather). The climate conditions can vary between locations and can play a major role in safety (ie, wet/hot weather). A shade cover (preferably waterproof cover) over the exercise equipment and a drinking fountain are recommended for participant's health and safety. Avoiding peak temperature and ultraviolet light exposure should also be practiced for organised, structured classes. 28 The presence of benches and sheltered resting areas are also important to allow the opportunity to rest, especially for those with reduced functional capacities. 29

| Intergenerational outdoor space
Older people often provide care for their grandchildren.
Approximately, 18% of children under 13 years are cared by their grandparents. 30 This presents an opportunity for a shared experience, either using the same equipment, or using co-located out-

| How to facilitate engagement of older people
There are several ways to increase and facilitate community and user engagement. First, the inclusion of signage is important in making the park salient, with effective cues and instructions to increase physical activity. 31,32 Inadequate instructional support and lack of relevant information for users can be barriers to using outdoor exercise equipment. 10 Providing clear instructions, on-site labelling and graphic illustrations can assist users to understand what to do and be independent users as well as assist in increasing efficient use of the equipment to achieve positive health outcomes. 33,34 For older people, providing supervision and instructional sessions by qualified exercise instructors can also positively engage older adults in outdoor exercise equipment use. 23,35 A recent study from Asia reported independent users spent less than 9 minutes on all outdoor exercise equipment combined, highlighting the lack of sufficient time spent to meet the minimum duration for physical activity recommendations. 36 Consequently, incorporating education and information around correct equipment use, adequate amount and intensity of physical activity are also required to achieve health benefits.

| How to increase participation/ uptake and adherence
Social connectedness has been identified as one of the key themes of users to attend and use outdoor exercise equipment. 10 Investment in park/site programming such as organised events or activities seems to be associated with higher park usage. 37 In fact, overall park use and physical activity was reported to decline by 39% due to a reduced number of organised programs in Southern California. 38 For older people, the social element of engaging in activities, fun and enjoyment are key motivators for older people to take part in physical activity 39 and they prefer to exercise with their same age group. 40 Training age-friendly senior ambassadors/ champions to act in community leadership roles and as role models can also greatly improve communication and engagement of older people to increase participation in programs, activities and events. Similar strategies have been employed by the National Heart Foundation Walking program which resulted in sustained engagement in outdoor physical activity (80% were still active after 6 months). 41 Designing outdoor activities with the use of outdoor exercise equipment should facilitate the opportunities for social interaction, the creation of new relationships and provide social support to motivate and encourage older people to engage in physical activities. 23,42 If the equipment is located close to a community centre, prior agreements can be made for the participants to use the space to share food and drink following the session. Similarly, scheduling regular times to meet and exercise (eg, organised session), so that people know when others will be there, can also facilitate ongoing participation.
Other important aspects to increase uptake of outdoor physical activity and community engagement include targeted marketing and promotion. 31,33 Consequently, to maximise outreach for older people to benefit from outdoor exercise equipment, a multilayer approach should be considered that incorporates targeted marketing, information, promotion and organised group activities. 43 Local governments plan and deliver services in health, recreation, planning and building control, and human and community services. As such, local governments, through their varying roles and levels of community engagement, can play a significant role in designing, facilitating and delivering safe outdoor active space for older people.

| CON CLUS ION
Commonly, outdoor exercise equipment is often suitable for ablebodied adults with little consideration for the physical needs of older people. The design of age-friendly outdoor spaces should be incorporated into decision-making using a set of age-friendly considerations, where the chosen equipment is safe, targets balance, functional strength and day-to-day movements and activities. Providing clear instructions and information, as well as promotion, organised activities and programs are important factors in maximising engagement and social connectedness of older people in the community in order to achieve positive health outcomes.

CO N FLI C T O F I NTE R E S T S TATE M E NT
The authors declare no conflicts of interest.