The goal of this clinical trial is to test the effects of the test products on the locomotor system in healthy Japanese adults with low muscle mass and knee joint discomfort. The main question it aims to answer is:
• Does the daily consumption of the test product improve subjective knee symptoms, quality of life (QOL), and physical function?
Participants will be asked to:
* Take 3 capsules of the test product daily for 12 weeks.
* Complete questionnaires regarding subjective knee symptoms and QOL.
* Undergo bilateral X-ray imaging.
* Undergo assessment of lower limb extension strength.
* Perform the stand-up test to evaluate lower limb muscle endurance.
* Perform the 10-meter walk test to evaluate walking ability.
* Undergo anthropometric and physical measurements. Researchers will compare Test Product 1, Test Product 2, and Test Product 3, against a placebo group to see if consumption of the study products improves knee symptoms, QOL, and physical function.