Bottle of 15 mL JUICE HA® supplement will be taken once a day for 12 weeks.

A 6-meter gait speed test will be conducted to assess walking speed. Participants will be instructed to walk at their usual pace over a distance of 6 meters, and the time taken to complete the distance will be recorded. Gait speed will be calculated by dividing the distance by the time, and a gait speed of less than 1.0 meter per second will be considered indicative of low physical performance.

Researchers received training in the administration of the Short Physical Performance Battery (SPPB) and were audited by the same trainer to ensure accurate and standardized execution. The SPPB, with a total score of 12 points, comprises three components: a standing balance test, a gait speed test, and a chair stand test. Based on the total score, participants are classified as frail (4-7 points), pre-frail (8-9 points), or functionally normal (10-12 points). Before testing, researchers explained the procedures and purpose of the assessments to the participants and demonstrated the key points of each movement. Participants were allowed one practice trial before formal testing. A 3-minute rest period was provided between the practice and formal test for each component.

The Sarcopenia and Quality of Life (SarQoL) questionnaire will be used to assess the quality of life in individuals with sarcopenia. The questionnaire can be either self-administered by the participants or administered with the assistance of researchers through verbal questioning. The SarQoL consists of 55 items grouped into 22 questions and is designed to be completed within approximately 10 minutes.

Blood samples were collected at five different time points (week 0, week 6, week 12, week 18, week 24). The scavenging ability of antioxidants (6-hydroxy-2,5,7,8-tetramethylchroman-2-carboxylic acid, Trolox) was determined using a curve, and the amount of Trolox equivalent to the test serum's inhibition rate was calculated. Next, the level of malondialdehyde (MDA), a standard biomarker of lipid peroxidation, was determined by an ELISA kit provided by the Caman Company (Cayman Chemical Company, Michigan, USA). As described in the protocol, the reaction mixture was boiled at 90-100°C for 60 min, and the absorbance at 550 nm was measured using an ELISA plate reader (Tecan GENios, A-5082, Austria). The values are expressed as micromoles of MDA per liter.

Blood samples were collected at five different time points (week 0, week 6, week 12, week 18, week 24). The concentrations of serum cytokines IL-6, IL-10, TNF-α, and high-sensitivity C-reactive protein (hs-CRP) will be measured using commercially available assay kits (Bio-Legend Inc., No. 430207, San Diego, CA) and enzyme-linked immunosorbent assay (ELISA) methods (Tecan GENios, A-5082, Austria). Absorbance readings will be taken at wavelengths of 450 nm, 545 nm, 520 nm, and 570 nm, respectively. The concentrations of IL-6, IL-10, TNF-α, and hs-CRP in serum samples will be calculated based on the corresponding standard curves.

Blood samples were collected at five different time points (week 0, week 6, week 12, week 18, week 24). Then will be assessed by measuring serum levels of mTOR and RSK (muscle synthesis markers) and MuRF1 and atrogin-1 (muscle degradation markers). These biomarkers will be quantified using commercially available assay kits and enzyme-linked immunosorbent assay (ELISA) methods (Tecan GENios, A-5082, Austria). Absorbance readings will be taken at wavelengths of 450 nm and 570 nm, respectively. The concentrations of mTOR, RSK, MuRF1, and atrogin-1 in serum samples will be determined based on the corresponding standard curves.