· Inclusion criteria.

1. 60~69 years old
2. Chinese residents living in the community
3. Have a smart phone with an internet connection at home, existing users of TikTok or have a willingness to download and use TikTok

Individuals with sarcopenia screening questionnaire: Five-item (strength, walking assistance, rising from a chair, stair-climbing, and falls) combined with calf circumference [SARC-CalF] ≥11 [2,32]

1. Individuals with possible sarcopenia, as defined by low Grip Strength [M:<28 kg, F:<18kg] in accordance with the 2019 Asian working group consensus on diagnosis criteria for sarcopenia [2]
2. Be able to attend the community health center (at their own expense if travel is required) on six occasions for the duration of the study
3. Informed consent for screening and research

· Exclusion criteria.

1. Unable to communicate or independently complete learning and exercise using TikTok
2. Serious or unstable medical illness, such as severe cardiovascular or respiratory conditions, mental disorder, dementia, etc.
3. Currently undertaking regular exercise (e.g. Tai Chi and Square Dance) and exercise intensity is moderate (≥ 150mins/week)
4. Contraindications for the use of Bioelectrical Impedance Analysis (BIA), such as people with implanted cardiac pacemakers, or other electronic devices or metal grafts, or with significant pitting oedema, or with limb dysfunction or body paralysis, or while taking medications that affect body composition, such as diuretics or glucocorticoids.

· Primary aim.

Evaluate the feasibility and acceptability of the research procedures, including:

1. Assessing recruitment capability and participant characteristics: Recording the recruitment process, including participant numbers screened, eligible, approached, consented, and excluded after screening; then calculating the relevant rates.
2. Assessing intervention and study procedures’ acceptability and suitability: a) Participants’ evaluation of the intervention and study procedures; b) Whether the rationale for participant dropout is associated with the intervention and study procedures; c) Participants adherence to the intervention including the compliance rate for completion of the entire study, health education, and exercise, respectively; d) Follow-up rate = Number of participants who complete the follow-up stage / Number of participants who complete the six-week exercise intervention.
3. Assessing data collection procedures and outcome measurements: a) Time needed to collect data; b) Experiences of the secondary outcome measures, such as whether they feel fatigued or burdened.
4. Assessing resources and the ability to conduct the study and intervention: a) Duration of time required to complete each step of this study; b) Ability to complete the study within the allotted time; c) Capacity of researchers to collaborate with community healthcare professionals; d) Evaluate researchers’ data organization, management, and analysis ability.
5. Assessing participant responsiveness to intervention: a) Investigate subjective experiences of the participants during the intervention; b) Measure objective outcomes before and after intervention.

· Secondary outcomes.

Table 1 outlines the two types of secondary outcomes that will be evaluated at various points throughout the study. The first category consists of muscle-related outcomes, including muscle strength, muscle mass, and physical performance. The second category includes additional body parameters such as anthropometric indices, nutrition state, perceived knowledge, personal motivation, behavioral skills, and monitoring of behavior change. The questionnaire survey, like MNA-SF, SEMCD-6, and the Self-Management for Chronic Disease Scale, will be conducted after the physical measurements are assessed. The PI will ask participants the questionnaire questions verbally and will record their answers electronically. If participants wish to see the questionnaires, they will be provided with a paper copy. Those measurements will take about 30–40 minutes in total to complete, which will be assessed in an office provided by the community health center.

Download:

• PPT
  PowerPoint slide
• PNG
  larger image
• TIFF
  original image

Table 1. Overview of instruments and time of outcome measures.

https://doi.org/10.1371/journal.pone.0303481.t001

· Handgrip strength.

Handgrip strength (kg) will be measured with a digital hand-held dynamometer (EH101, Xiangshan Inc, Guangdong, China). In a seated position with the elbow flexed at 90 degrees, the shoulder attached to the thorax, and the wrist in a neutral position (0 degrees), the maximal grip strength is measured. The measurements are taken three times on each side (left and right), with a 30-second interval between each assessment [35].

· Anthropometric measurements.

Height will be measured to the nearest 0.1 cm using a stadiometer, and weight will be measured to the nearest 0.1 kg using a scale. Calf circumference and abdominal circumference will also be measured using a tape measure for both legs and the navel, respectively, to the nearest 0.1 cm.

· Body composition.

Body composition measurement will be conducted using a multi-frequency bioelectrical impedance analyzer device (InBody S10; Biospace, Seoul, Korea) according to the manufacturer’s guidelines. BIA calculates body composition by comparing the conductivity of various tissues based on their distinct biological properties. As a cell approaches an ideal spherical shape, its conductivity decreases, as it is proportional to water content and, more specifically, electrolytes. Since adipose tissue is composed of round-shaped cells and contains relatively little water in comparison to other tissues such as muscle, the conductivity of the body will decrease as body fat increases. In order to conduct a multi-segment frequency analysis, electrodes are set at six precise tactile points of the body. Using six different frequencies (1 kHz, 5 kHz, 50 kHz, 250 kHz, 500 kHz, 1000 kHz), more than 30 impedance measurements are obtained from the right and left arms, trunk, and right and left legs [36]. The following body index parameters will be chosen for analysis in this study: skeletal muscle mass (kg), skeletal mass index (kg/m²), upper-extremity skeletal muscle mass (kg), lower-extremity skeletal muscle mass (kg), trunk skeletal muscle mass (kg), body fat (kg), body fat percentage (%), body mass index (kg/m²), protein (kg), and bone mineral (kg).

· Physical performance.

Physical performance will be measured by using a 4-Meter Walk Test (4- MWT, m/s) and a Five Times Sit to Stand Test (FTSST, s).

First, the participants’ self-selected walking speed will be measured using a 4-MWT (with 2m for acceleration/deceleration) [37]. At the beginning and end of the timed walkway, space will be provided for participants to accelerate and decelerate outside of the data collection area to reduce gait variability introduced during these phases. Participants will be instructed to "walk at a comfortable, normal pace" until reaching the end of the marked path; and each participant must accomplish three consecutive measurements. A researcher will measure walking time using a stopwatch (ZSD-013, China), starting it when the participant’s lead leg crosses the first marker and stopping it when it crosses the second marker. To prevent interobserver variation, all stopwatch measures will be conducted by the same researcher. Throughout the testing session, participants will be provided with breaks as required.

Second, participants will sit on an armless chair with a 43 cm (cm) seat height to commence the FTSST [38]. Each participant will be instructed to sit with their back against the chair’s backrest and their arms crossed over their torso. The researcher will then demonstrate the proper technique for performing the test, including coming to a full stand, which is defined as an upright trunk with extended hips and knees. A researcher will measure the time using a stopwatch (ZSD-013, China). Timing will commence when the researcher says "go" and end when the participant’s glutes touch the seat after the fifth stand [39]. The participants must stand and sit five times "as quickly as possible" and without physical assistance. The researcher will not use encouraging words or body language to encourage participants to speed up their performance.

· Nutritional status.

The Mini-Nutritional Assessment Short Form (MNA-SF), a valid nutritional screening instrument applicable to geriatric health care professionals, will be used to evaluate nutritional status [40]. The MNA-SF consists of six items and one anthropometric measurement (either body mass index [BMI] or calf circumference [CC]) to identify individuals at risk of malnutrition. Maximum MNA-SF score is 14, with scores≤11 indicating possible malnutrition and scores ≥12 confirming normal nutritional status [41]. MNA-SF, having fewer items than Full-MNA, requires less measuring time while achieving similar predictive power as Full-MNA [40,42].

· Perceived knowledge.

Participants’ perceived knowledge of sarcopenia prevention will be assessed by using true or false questions. The 21 questions reflect the main points of the seven topics in the sarcopenia prevention health education strategy. Final evaluation of the participants’ mastery of health education knowledge will be based on the proportion of correct responses. These sarcopenia quizzes were developed in our previous study [23], which involved a literature search, followed by two rounds of PPI consultations (eight older adults, four sarcopenia and health education experts) and two rounds of focus group interviews (31 older adults with possible sarcopenia). All these stakeholders reviewed and approved the content of the questions which lends itself to content validity.

· Personal motivation.

Self-Efficacy for Managing Chronic Disease 6-item Scale (SEMCD-6) developed by the Stanford Patient Education Research Centre in a Chronic Disease Self-Management Program will be used to identify and measure the confidence level of older adults in adopting appropriate behavioral skills to prevent and manage chronic disease [43,44]. Scores on this scale are calculated as the means of the six items, including self-efficacy to manage symptoms (4 items) and self-efficacy to manage disease (2 items), each measured on Likert scales ranging from 1 (not at all confident) to 10 (totally confident). The higher the score, the greater the participant’s confidence in completing the disease management mission. Measures of SEMCD-6 reliability have been found to be high (= 0.91), and test-retest reliability has been reported to be statistically significant (r = 0.87).

· Behavioral skills.

Self-management Behavior for Chronic Disease Scale also developed by the Stanford Patient Education Research Centre will be used to identify and measure older adults’ actual behavioral skills in daily life for preventing and managing chronic disease [43–45]. The scale includes exercise management (5 items), cognitive symptom management (6 items) and communication with physicians (3 items). Exercise management is measured by examining the total time spent engaging in physical activities, such as stretching and strengthening exercises, walking, swimming, bicycling, and aerobics (categorized respectively as 0: none, 1:<30min/ week, 2: 30-60min/week, 3: 1-3h, or 4: >3h/week). Cognitive symptom management is measured on a 6-point Likert scale, ranging from never to always, and includes distraction, progressive muscle relaxation, imagery, positive thinking, and self- distance. Communication with physicians is measured as the number of times the participants prepared a list, asked questions, and discussed problems with the provider on a 6-point Likert scale ranging from never to always.

· Behavior change monitoring.

Three aspects of behavior change will be monitored throughout the entire research procedure, including: 1) Exercise adherence during the intervention and follow-up periods will be calculated by completion rate of minimum exercise required in the study. The Exercise Adherence Rating Scale (EARS) is a validated 16-question instrument with a 6-question subscale assessing adherence; the remaining questions measure reasons for adherence/non-adherence. As stated in the study [46], EARS is a valid and reliable tool that allows for the assessment of compliance with suggested home exercise. The six items comprise a unidimensional scale that exhibited favorable measurement features, including satisfactory internal consistency and strong test-retest reliability. 2) Percentage of participants who actively view and share sarcopenia-related information to others. 3) Percentage of participants willing to formulate habits of regular exercise to prevent sarcopenia at the end of the current study. 4) Exposure percentage of exercise and sarcopenia-related videos = Number of exercise and sarcopenia related videos viewed / Twenty videos. TikTok can push videos to users that they are interested in based on big data algorithms; therefore, if participants begin to view more videos about exercises and sarcopenia after health education in our research, TikTok will capture these changes in their viewing habits and push more videos about exercises and sarcopenia to them. Then, researchers can record the number of exercise and sarcopenia-related videos when every twenty videos are viewed on participants’ TikTok and observe the exposure percentage of exercise and sarcopenia-related videos to determine if participants’ video-scrolling behavior changes.

· Social-demographic information.

The participants will respond to single-item questions regarding their age in years, gender, long-term condition, medication, level of education, and any significant health issues that may impact their ability to engage in physical activity, as well as whether they use a mobility aid.

· Qualitative Interview.

After the six-week follow-up period, all participants, including those who withdraw at any point, will be offered a semi-structured interview in an office provided by the community health center to assess their experiences with the intervention and research process. This will take about 30min. Family members/ caregivers may also be invited to the interview at the request of the participant.