Sarcopenia prevention and management are highly prioritised goals in the Healthy Ageing agenda. The study aims to: 1) evaluate the effects of the digital-enhanced, volunteer-engaged collaborative care pathway to improve sarcopenia, reduce fall risk, and increase health-related quality of life (HRQL) among community-dwelling older adults with risk of, or diagnosed with, sarcopenia; 2) evaluate whether the volunteers who received health coach capacity training and supported the intervention experienced health benefits across time; 3) explore the engagement experiences and perceived effects of elderly participants with sarcopenia during the program; 4) evaluate the intervention implementation process and effects from the perspectives of social care workers.

Population ageing is accelerating worldwide, and the widening gap between life expectancy and healthy life expectancy is increasingly driven by late-life declines in physical function and mobility. Sarcopenia-an age-related, progressive syndrome characterised by reduced skeletal muscle strength and mass/quality with impaired physical performance-has become a key modifiable determinant of frailty, falls, disability, hospitalisation, and mortality among community-dwelling older adults. Using the Asian Working Group for Sarcopenia (AWGS) criteria, a systematic review and meta-analysis of studies in China reported a pooled prevalence of 12.9% among community-dwelling older adults. In Hong Kong, approximately 9% of adults aged 65 and above are diagnosed with sarcopenia, indicating a substantial community burden. Beyond functional loss, sarcopenia is associated with increased healthcare utilisation and costs, evidence suggests higher risks of hospital admission and longer length of stay among older adults with sarcopenia, contributing to considerable economic impact.

Contemporary consensus definitions (e.g., EWGSOP2 and AWGS) identify low muscle strength as the central feature, with muscle quantity/quality and physical performance used to confirm diagnosis and grade severity, which aligns management with interventions targeting strength, function, and nutritional status. Accordingly, guideline-based care emphasizes two key modalities: optimizing nutrition-particularly adequate protein intake to support muscle protein synthesis and, where indicated, correcting vitamin D deficiency-and implementing exercise programs centered on progressive resistance training, often complemented by functional and balance components to improve mobility and reduce falls risk. Evidence further suggests that combined exercise and nutritional strategies can outperform single-modality approaches for improving outcomes relevant to sarcopenia, including strength and physical performance.

Despite substantial evidence supporting lifestyle interventions, particularly exercise and nutritional optimization-for improving sarcopenia-related outcomes, these benefits are often time-limited in practice. When structured program support ends, the effective intervention "dose" commonly declines (e.g., reduced training frequency/intensity and weaker adherence to dietary targets), and improvements in strength, function, and overall physical performance may attenuate accordingly. This pattern is consistent with real-world evidence indicating that sustained benefits depend heavily on continued participation and adherence, with lower adherence associated with smaller functional gains than those observed under supervised or trial conditions. Therefore, for a progressive and chronic condition such as sarcopenia, the key challenge is not only initiating behavior change but ensuring that exercise and dietary practices are maintained and embedded into daily routines so that benefits can persist.

The above evidence underscores a key gap in sarcopenia management: many interventions and service models have limited capacity to sustain lifestyle behavioural changes over time. Maintenance requires that evidence-based recommendations be translated into routinised daily practices, supported by (i) person-centred assessment and tailoring, (ii) empowerment and goal-oriented self-management, and (iii) ongoing social reinforcement (peer/volunteer support) with timely follow-up. The WHO Integrated Care for Older People (ICOPE) framework provides a pragmatic structure to operationalise these requirements through intrinsic capacity assessment, personalised care planning, and continued community follow-up.

To address the above gaps, the VELO-S project proposes a 12-week, volunteer-engaged lifestyle optimisation programme grounded in WHO ICOPE and delivered through an ICOPE-based critical pathway for nutrition and exercise. VELO-S is enabled by a digital platform that contains an exhaustive checklist of person-centred risk factors and corresponding, precise lifestyle activity recommendations for each care pathway (nutrition and physical activity). After baseline screening, trained social care workers conduct care mapping to identify each participant's key barriers and preferences, select relevant risk factors within the platform, and generate a tailored set of recommended lifestyle actions. A simple personalised report summarising risk factors and agreed actions can then be produced (electronic or hard copy) for participants and the matched health coach, supporting shared understanding, goal-oriented follow-up, and iterative adjustment. In parallel, VELO-S incorporates goal-oriented empowerment and volunteer-enhanced interactive lifestyle empowerment workshops to strengthen motivation, social support, and practical capability for maintaining nutritional and activity changes, thereby targeting the sustainability mechanisms required to deter sarcopenia progression in community-dwelling older adults.

This overall study aims to evaluate the effects and implementation of VELO-S among community-dwelling older adults with pseudo-sarcopenia or sarcopenia.

The objectives of this study are to (1) examine the effectiveness of a 12-week VELO-S intervention compared to an attention control in improving appendicular skeletal muscle mass, handgrip strength, physical mobility function, risk of sarcopenia, frailty, nutrition, physical activity, and health-related quality of life among community-dwelling older adults with sarcopenia risk or sarcopenia at 12 weeks post-intervention and 24 weeks follow-up; (2) to examine changes in health-related quality of life and mental health among volunteers who participated in the health coach capacity training at 12 weeks post-intervention delivery and 24 weeks follow-up, compared to baseline; (3) to explore the engagement experiences and perceived effects of elderly participants with sarcopenia during the program; (4) to explore the perspectives of social care workers on their experience on intervention effects and implementation process.

Inclusion Criteria:

1. aged 60 or above
2. Pseudo-Sarcopenia as indicated by a score on SARC-CaIF ≥11, OR sarcopenia according relative BIA-based appendicular skeletal mass/ height (Men: <7 kg/m2; women: <5.7 kg/m2), OR handgrip strength on dominant hand (male <28 kg, female <18 kg) (Chen et al., 2025)
3. the ability to use a smartphone, electronic tablet, or computer
4. consent to participate

Exclusion Criteria:

1. having medical conditions contradictory to physical activity including unstable cardiovascular and orthopaedic conditions
2. engaging in other structured health promotion program involving physical activity and nutritional enhancement

Outcome assessors will be blinded to the intervention assignment results.