Can a phone app replace the gym for seniors with muscle loss?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria * Individuals diagnosed with sarcopenia according to both the European Working Group on Sarcopenia in Older People (EWGSOP) criteria and the Asian Working Group for Sarcopenia 2019 (AWGS 2019) criteria * Individuals with reduced muscle strength, defined as at least one of the following: * Handgrip strength \< 28 kg for men or \< 18 kg for women * Five-times Sit-to-Stand Test time \> 12 seconds without arm support * Individuals with reduced muscle mass, defined as at least one of the following: * Skeletal Muscle Mass Index (SMI) \< 7.0 kg/m² for men or \< 5.4 kg/m² for women measured by DXA * Skeletal Muscle Mass Index (SMI) \< 7.0 kg/m² for men or \< 5.7 kg/m² for women measured by BIA * Individuals able to independently perform sit-to-stand movements * Individuals with sufficient physical and cognitive capacity to participate in the exercise program * Individuals able and willing to provide written informed consent * Individuals able to operate a mobile phone independently or with assistance from a caregiver Exclusion Criteria * Individuals with cognitive impairment, defined as a Mini-Mental State Examination (MMSE) score \< 20, or those unable to participate due to cognitive decline * Individuals with an implanted cardiac pacemaker or other implanted electronic medical device * Individuals with uncontrolled cardiovascular disease despite appropriate medical management * Individuals who have undergone lower-limb surgery within the past 6 months and are unable to ambulate independently * Individuals with moderate-to-severe musculoskeletal pain or functional limitations that interfere with objective functional assessments * Individuals with severe obesity, defined as a body mass index (BMI) \> 50 kg/m² * Individuals currently receiving active cancer treatment or experiencing severe systemic frailty * Individuals with hemiplegia that prevents participation in the prescribed exercise program * Individuals who are anticipated by the investigator to be unable to complete the study procedures or follow-up assessments * Individuals unable to understand or comply with study instructions provided in Korean * Individuals considered unsuitable for study participation at the discretion of the investigator for any other reason