Table 2.

An overview of variables and outcomes, outcome measures, instruments and time point for the assessment

Outcome	Outcome measures	Instrument	Time point
Descriptive variables
Personal information	Age, gender, former job, marital status, educational background and chronic diseases	Self-report	T3
	Depression	The Major Depression Inventory (MDI) [39]	T3
	Incontinence	International Consultation on Incontinence Questionnaire (ICIQ) [40]	T3
	Eating ability	Self-reported dental state	T3
		The Eating Symptom Questionnaire [41]
		The EAT-10 Questionnaire [42]
		Simplified Nutritional Appetite Questionnaire [43]
Primary outcome
Muscle power	Lower leg muscle power	The Nottingham Leg Rig [44–46]	T3 and T5
Secondary outcomes
Muscle mechanical function	Countermovement jump	The countermovement jump is performed on a force platform (Kistler 9281 B, 40 × 60 × 5 cm) following the procedure described in [47]. Four maximal jumps will be performed with 1-min interval and the highest jump recorded	T3 and T5
Maximal muscle strength	Leg press	Assessed on the dominant leg in a custom-built unilateral leg press device with a fixed footplate instrumented with piezoelectric force transducers (Kistler 9367/8 B). The force signals will be digitally sampled at 1 kHz while on-line visual feedback is provided to the subject. The contractile rate of force development and impulse will be determined in the trial with the highest resultant peak force [44, 48]	T3 and T5
	Handgrip strength	Handgrip strength is measured using a handheld dynamometer (Original Smedley’s Daynameter, Scandidact, 100 kg, Cat. No. 281128). Participants are instructed to sit with the elbow at a 90° angle, the wrist in neutral position. The inner lever of the dynamometer is adjusted to the hand of the participants (the second phalanxes against the lever) (Andersen-Ranberg et al. 2009). A minimum of three contractions in each hand will be performed and testing continues until participant produce less force than the prior test.	T3 and T5
Physical Frailty Status	The SHARE-FI75+ Fried frailty phenotype	The SHARE-FI75+ is a physical frailty assessment tool that is developed specifically for community-dwelling adults aged ≥ 75 years [5]	T3 and T5
		Fried frailty phenotype consists of five variables where three are based on questions: (i) unintentional weight loss, (ii) self-reported exhaustion, and (iii) low energy expenditure and the remaining two are based on objective assessment: (iv) slow gait speed and (v) weak hand grip strength [9]. The variable ‘low energy expenditure’ is modified to follow the current recommendations on physical activity in older adults from the World Health Organization [49].
Risk of malnutrition	Protein intake	The Protein Screener Pro55+ is used to assess the risk of poor protein intake [35]	T1, T2, T3 and T5
		Four days food records (filled out on three weekdays and one day during the weekend) are calculated (Winfood 4.1) to estimate the average protein intake (g) per kg body weight per day and protein content per meal. In addition, energy intake and distribution of macronutrients are calculated.
	Weight loss	Self-reported unintentional weight changes during the last month	T1, T2, T3, T4, and T5
	Nutritional status	The Eating Validation Scheme (EVS) is composed of five questions about dietary intake and weight loss and three questions about risk factors (dysphagia, eating assistance, and acute illness) [50]	T3 and T5
		The Mini Nutritional Assessment (MNA) is composed of 18 questions and measurements concerning appetite, eating ability, weight, need for help, illness, and medication [51]
Anthropometry	Weight	Measured in light clothes, without shoes and subtracting 0.5 kg for the weight of clothes using a calibrated TANITA scale (model DC430SMA)	T3 and T5
	Waist- and Hip- circumference	Following the protocol by the World Health Organization [52]
	Height	Measured without shoes	T3
Body composition	Estimation of fat mass, fat-free mass and bone mass	Dual-energy X-ray absorptiometry (DXA) (Lunar Prodigy) scans will be used to assess whole body composition with special emphasis on lean mass and fat tissue as well as bone mineral density.	T3 and T5
		Foot-to-foot bioelectrical impedance analysis (BIA), using the TANITA Total Body Composition Analyzer (model DC430SMA).
Physical function and mobility	Gait speed, Chair stand, Balance	The Short Physical Performance Battery (SPPB) [53]	T3 and T5
		Rising from laying position on the floor and stand and reach test [54]
		Self-selected and maximal gait speed (10 m) [55–57]
		Distance walked during 2 min [58, 59]
Physical activity level	Objective measures of intensity, duration, and patterns of physical activity and sedentary behavior	Hip-worn accelerometers, ActiGraph (removed during sleep)	T3 and T5
		Thigh-worn accelerometers, Axivity (24 h/day)
		Data will be continuously collected in a raw format at 30/50 Hz, respectively, over a period of 7 days.
	Self-reported sedentary behavior	The Sedentary Behavior Questionnaire (SBQ) [60]	T3 and T5
Activities of daily living	Self-report	Questionnaire that combines items from the Most Efficient Lists and the Short-Form of Late-Life Function and Disability Instrument [61–63]	T3 and T5
Pain, fatigue, and fatigability	Self-report	The Brief Pain Inventory - Short Form (BPI-sf) [64]	T3 and T5
		The Mobility fatigue scale “Mob-T” [65]
		The Pittsburgh Fatigability Scale (PFS) for older adults (only the domain about physical fatigue will be assessed) [66]
Fear of falling	Self-report	The Falls Efficacy Scale – International (FES-I) [67]	T3 and T5
		Self-reported falls within the last year
Cognitive function	Pencil and paper test	The Digit Symbol Substitution Test (DSST) [68, 69]	T3 and T5
Health-related quality of life	Self-report	The EQ-5D-3L questionnaire [70]	T3 and T5
Biomarkers	Blood sample	Biomarkers related to nutritional status, physical activity, sedentary behavior, as well as physical and cognitive function—such as lipids, hormones, proteins, cytokines, vitamins, and minerals, e.g., cholesterol, HbA1c, adiponectin, suPAR, Crp, IL-6, B12 and vitamin D, vitamin B12 [71–74]	T3 and T5

T1 time of enrolment, T2 post the stabilization phase, T3 baseline pre-intervention, T4 half-way follow-up, T5 close-out post-intervention