Table 1 General information of the ERS and SMS interventions

ERS intervention

Aerobic training. Strength-based/ endurance exercises. Balance-based functional exercises. Flexibility exercises.

Specially trained PA specialist: physical therapist; sport professional/trainer; ergotherapist with specific health qualification. Sessions will be always performed under the supervision of the same trainer.

16 weeks. Two sessions per week of 45–60 min. Ask each participant to perform a third session on their own such as a 30-min walk. The intervention will be conducted in an indoor primary-care or sports facility. Municipality facilities (e.g. activity centres for older adults).

All training sessions will begin with a 5–10 min warm-up focusing on social and physical interactions. Followed by 35 min of different exercises adapted to each individual’s functional level (according to the participants’ SPPB score^a). All training sessions will end with cool-down (breathing exercises and stretching for 5–10 min.

SMS intervention

Raising awareness on differences, associations, risks and benefits of SB and PA. Setting personal activity goals (long-term achievement goals). Enhancing motivation. Goal-setting focusing separately on SB and PA. Self-monitoring (pedometer and activity diary). External monitoring (instructor). Problem-solving according to the IDEA.^b Social influence and social support. Raising awareness on facilitators and barriers of PA and SB at home and neighbourhood. Environmental signposting.

The same specialist for the ERS intervention.

Total of 30 weeks. 1 one-to-one session (week 1; 40 min). 6 group-based sessions (weeks 3, 4, 5, 7, 9 and 11; 45–60 min). 4 telephone calls (weeks 15, 20, 25 and 30; 20 min).

The SMS sessions include the following activities: introducing the project to the participant, developing a rapport, setting a meaningful long-term goal to be achieved at the end of the intervention, identifying facilitators and barriers of PA and SB at home and neighbourhood in a group dynamic, environmental signposting to help engaging participants in local opportunities to do PA, checking daily step counts registered in the activity diary and setting individual goals to increase steps or other physical activities, setting individual goals to reduce siting time set choosing recommendations (SITLESS tips) for decreasing SB, problem-solving techniques to overcome barriers to being less sedentary and more active according to the IDEA^b problem-solving.