This study aimed to conceptualise for a real-life, cognitively enriched walking program for older adults, using a co-design process with academic experts and end users.
Cognitive tasks – The experts concluded that the cognitive tasks, used for cognitive enrichment of a walking program for older adults, should primarily target executive functioning and higher-order thinking as well as memory and learning. This is in line with the literature stating that these cognitive abilities are more susceptible for age-related decline as well as benefit the most from an intervention (7, 11, 21). The cognitive tasks the experts agreed on targeted these cognitive functions and were also considered feasible for cognitive enrichment of a walking program.
When presented to the end users, some cognitive tasks were seemingly preferred over others. For instance, a quiz scored better than an N-back task (i.e. react if a stimulus matches with the stimulus n trials before). Despite the aim to only select the most optimal cognitive tasks for the program, it appeared to be more beneficial to include all tasks. First, the experts agreed that all tasks were suitable and some of them explicitly mentioned that providing a wide range of tasks would yield better results than focusing on a few (i.e. better mimicking the real-world, increasing chances of far transfer effects, and preventing the program from becoming monotonous). Second, including a range of tasks will increase the chances of meeting everyone’s preferences as it became apparent in the survey that end users sometimes had divided opinions on certain tasks. And third, literature on self-determination theory shows that providing a pool of different tasks to choose from will introduce freedom of choice, which will support the basic psychological need for autonomy, and thus, increase autonomous motivation (22). Therefore, all cognitive tasks will be included in the program.
Refinement and further elaboration of the cognitive tasks was needed after considering the comments and suggestions from the experts and end users, especially for cognitive tasks that received low suitability scores. More specifically, tasks were integrated better in the walk so that performing them while walking would feel more natural. For instance, for the cognitive task ‘obstacle walk’, it was recommended to use natural obstacles (e.g. a fallen tree) instead of artificial objects. In addition, different and increasing complexity levels were provided for every cognitive task to make the program feasible and challenging for every individual, despite interindividual differences. For instance, index cards were developed for the cognitive task ‘hidden word’ containing five different words ranked from easy to difficult. If a participant successfully describes the first (easiest) word, he/she will be encouraged to describe the second (more difficult) word. This is consistent with the review of Wollesen (2014) stating that the cognitive challenge should be appropriate for each individual and should have increasing demands in order to gain better cognitive effects (23). Next, more variation was created within the tasks. For instance, in one variation of the task ‘noticing and remembering symbols’ photos were used that refer to an overarching theme (e.g. a local celebrity, a historical event). Thus, participants do not only have to search and remember the symbols, they also have to figure out the overarching theme. Finally, better framing of the cognitive tasks was added to increase participants understanding of the usefulness and potential benefits of each task.
Program characteristics – Recommendations were formulated on the characteristics of the program. First, the cognitive load during the walk should be sufficient, but not too high. The experts recommended that minimum 15–20 minutes should be allocated to cognitive tasks during a 30 minutes’ walk. However, they mentioned that more research is needed to find strong, scientific grounds for the precise dose. Most end users stated to be willing to perform cognitive tasks during a walk, as long as there is still enough time to fulfil other walking goals (e.g. rest and relaxation, spontaneous small talk, brisk walking).
Second, the walk should take approximately 30–60 minutes depending on the physical capabilities of the participants. This is a common duration for walking programs in Flanders (Belgium) (24) and, according to the survey, this duration should be feasible for more than 90% of the end users. Moreover, exercise interventions of 45–60 minutes were associated with cognitive improvements in the meta-analysis of Northey et al. (2018), while shorter (< 30 min) and longer (> 60 min) ones were not (7). In addition, they found that the exercise intervention should at least be of moderate intensity. This finding is in line with the concerns of some experts and end users in the survey, i.e. to keep an eye on walking pace as walking pace, and thus intensity, might decrease due to the simultaneous execution of cognitive tasks. In fact, a meta-analysis of Smith et al. (2015) found a reduction in gait speed under dual-task conditions in older adults (25). A few minutes of brisk walking before engaging in the cognitive tasks can be used to increase participants’ heart rate. Thus, the walk can be divided into three parts: (a) a warm-up of (brisk) walking for 5–10 minutes; (b) cognitive tasks for a larger part of the walk (approximately 15–20 minutes per 30 minutes of walking); (c) spontaneous small talk or rest and relaxation for the last 5–10 minutes.
Third, the experts agreed that the program should be organized at least twice a week to potentially obtain positive effects on cognition, which echoes previously reported findings (23). However, the meta-analysis of Gheysen et al. (2018) found no significant influence of session frequency on the cognitive effects of PA + CA interventions (10). As the precise dose-response relationship remains unclear, some experts proposed to give the participants as many occasions to engage in PA + CA as possible. However, the minimal frequency of twice a week does not coincide with the preferred frequency of the end users since only a minority of them indicated to be willing to participate twice a week or more. Moreover, about a quarter of end users reported not to be willing to participate in a cognitively enriched walking program at all. It is therefore of utmost importance to (a) address the current concerns of the end users and take up their suggestions; and (b) improve the attractiveness of the program by implementing motivational strategies as described in the systematic review of reviews of Zubala et al. (2017) on the promotion of PA interventions for community dwelling older adults (14). Furthermore, participants should receive the option to engage – alone or with friends/family – in cognitively enriched walks outside the organized walking sessions (e.g. by a home program).
Fourth, it is recommended to include occasional competition, but only if the participants are open for it. Previous research showed that competition can be a motivating factor for many older adults to engage in different types of games and to challenge themselves to do better (26). Indeed, this study confirms that friendly competition can be a good motivator for some, but it can also induce negative feelings in others. Thus, competition should always be implemented carefully while considering participants’ needs and preferences. Competition is preferably introduced as a friendly strive between teams rather than between individuals, or as a strive to obtain a certain goal rather than a strive against each other.
Additional suggestions for implementation – Attention should be payed to safety and fall risk during the walk. For example, by (a) ensuring that the cognitive tasks are not too challenging and thereby take away from the safety of walking, (b) using safe walking trails, (c) providing general instructions to improve safety, (d) conducting a fall-risk screening of each participant beforehand, and (e) paying extra attention for those at higher risk of falling. In addition, it is recommended to keep the walks fun, and not too serious, especially when competition is included.
Strengths and limitations – The main strengths of this study are that (a) the input from different angles throughout the co-design process resulted in the unique combination of experts’ and end users’ opinions, (b) each respondent could express their views anonymously, while ultimately providing information for an entire group, and (c) that no geographical constraints on the selection of experts was present and all Dutch-speaking end users could participate due to the online format of this study. However, recruiting for the survey took place online and through (walking) organisations for older adults which might have led to the overrepresentation of high-functioning, physically active respondents and the underrepresentation of those from lower socioeconomic groups and aged 85 years or above. Second, there were low response rates in the Delphi study and high drop-out rates in the survey. This could be explained by the high levels of commitment and time investment that were required, i.e. experts were asked to participate in several rounds and end users had to fill in a relatively long survey. Also, the coincidence of the final Delphi round with the start of the Covid-19 pandemic may have negatively affected response rate for the Delphi study, and the lack of digital skills in older adults may have positively affected drop-out rates in the online survey for end users. Third, an online survey is not the most optimal methodology to obtain in-depth insights in people’s opinions and experiences. However, in the light of the pandemic, it was the best way to safely gather input from a large group of end users.
Future directions – The next step is to translate the concept that resulted from this research into an actual cognitively enriched walking program for older adults aged 65 and above. An RCT will be performed to evaluate the enjoyability and feasibility of this program and its effectiveness to improve cognitive function and physical activity. In addition, a potential next step for future research is to investigate which adaptations are needed to make the program acceptable and effective for older adults with mild cognitive impairments or dementia.