Textbox 1.

RCT and intervention design

The multi-level cluster RCT tested two interventions among office workers. 263 office workers from two Swedish companies (73% women, mean age 42 ± 9 years, education 15 ± 2 years) (O’Cathain et al., 2015) were grouped into 22 cluster teams. At both companies, teams were randomized to one of two intervention groups or a wait-list control group. During the 6-month intervention period, one intervention group (iPA) focused on increasing moderate to vigorous physical activity (MVPA) and the other on reducing SED (iSED) by breaking up prolonged bouts of sitting and replacing SED with light-intensity physical activity to improve mental health and cognitive functions. The primary outcomes were accelerometer-measured time spent in MVPA and SED, while mental health and cognitive functions were secondary outcomes. The trial was conducted from 2018 to 2020. Ethical approval was obtained from the Stockholm regional ethic review board (2018/587–32). The intervention design was based on the Ecological model of health behaviour (Ojo et al., 2019,) which suggests that factors on the organizational, environmental, and individual level influence health behaviour. Multiple behaviour change techniques were included to address these different levels, see Figure 1. The design was also informed by a preceding study on perceived barriers and facilitators for reducing SED among office workers at the same companies (Nooijen et al., 2018). The three most reported barriers were sitting is a habit (67%), standing is uncomfortable (29%) and standing is tiring (24%). Standing (33%) or walking meetings (29%) and more possibilities or reminders for breaks (31%) were most frequent suggestions for facilitators. The interventions aimed at changing movement behaviour during work and non-work time. Organizational level: To ensure organizational support, human resource and higher management staff promoted participation in the interventions within their companies. In addition, the RCT aimed at recruiting managers as team leaders to provide manager support by acting as role models and by encouraging respective behaviours throughout the intervention period. They were also asked to promote continued participation in the interventions. Environmental level: Managers functioning as team leaders were expected to implement group activities and access to standing and walking meetings (see Figure 1). In addition, iPA participants received free gym access. Team leaders were invited to one individual and one group meeting prior to intervention start where they received information about their role as team leaders and the importance of PA or SED. Throughout the intervention period, team leaders could contact the responsible researcher for questions or support. Individual level: Both intervention groups received five counselling sessions based on cognitive behavioural therapy (CBT) and motivational interview (MI). Trained health coaches received additional training in applying CBT and MI. A detailed manual was used to standardize each session. Following CBT-based techniques were used: (1) Goal setting tied to internal rewards and value, (2) Identification of the individual’s resources and barriers for making behaviour changes, (3) Functional analysis including antecedents and consequences of undesired and desired behaviour, (4) Acceptance techniques for handling negative emotions, (5) Plan for long-term behaviour change. Between sessions, participants were asked to manually track their PA or SED using a logbook. Participants chose physical activities according to their individual needs and preferences.