Table 1 Intervention description: Content of exercise program (12 weeks) in the various ProMuscle interventions

Setting

Training at university in room equipped as gym location for the trial.

Training at local care organization in room equipped as gym location for the trial (in neighbourhood of older adults).

Training at training room of the local physiotherapist practice (in neighbourhood of older adults).

Frequency

Two times per week for one hour.

Two times per week for one hour.

Two times per week for one hour.

Intake

No intake consultation. Medical assessment was performed during inclusion.

No intake consultation. Before the start of the program, physiotherapists received participants’ medical and baseline strength-related measures from researchers.

Individual intake consultation with physiotherapist, to assess training level, potential injuries, and medical status.

Supervision

Researcher assisted by trained students. One trainer per two participants. 5-6 participants per group.

Physiotherapists and their assistants. Two to three trainers per group. 4-7 participants per group.

Physiotherapists and their assistants. One trainer per group. First 2-3 weeks: two trainers. 5-8 participants per group.

Type of guidance

Researcher organized individual training schedules; individual guidance during exercise performance.

Physiotherapists organized training sessions according to detailed training protocol. Tailored the training intensity when necessary (e.g. in case of an injury).

Physiotherapists used the protocol as a guideline for creating a training schedule and tailored the training intensity to individuals’ capabilities and limitations.

Training session structure

Warming-up; progressive resistance exercises on leg press, leg extension, chest press, lat pulldown, pec deck, and vertical row machines; warm-down. Focus on main muscle groups.

Warming-up; progressive resistance exercises on leg press, leg extension, chest press, lat pulldown, and vertical row; warm-down. Focus on main muscle groups.

Dependent on training location, including: Warming-up; progressive resistance exercises on leg press, leg extension, back extension, pull down, cable row, chest press; warm-down. Focus on main muscle groups. Tailored to individual needs: cardio exercises (exercise bike, treadmill, cross trainer), squats with free weights.

Workload

Started at 3-4 sets of 10-15 repetitions (50% of 1-RM) and increased toward 3-4 sets of 8-10 repetitions (75% of 1-RM).

Leg exercises: started with 3-4 sets of 15 repetitions (50% of 1-RM) and increased toward 4 sets of 8 to 12 repetitions (75%-80% of 1-RM). Other exercises: According to insights of physiotherapist. Adjustments made e.g., in case of injury.

Leg exercises: Started with 3-4 sets of 15 repetitions (50% of 1-RM) and increased toward 4 sets of 8 to 12 repetitions (75%-80% of 1-RM) (location 1). Building up intensity according to own insights and based on 3-RM measurement on leg press and leg extension, intensity was on average increased with 5% per weight increase (location 2). Other exercises: According to insights of physiotherapist. Adjustments made e.g., in case of injury.