Development and Strategic Research of Practical Applications in Sports Nutrition

This study evaluates the practical feasibility and potential effects of an 8-week dairy product intervention in physically active adults aged 18-39 years. Participants will consume a dairy product enriched with high protein, calcium, and vitamin D under real-life conditions. Assessments will be conducted before the intervention, after 4 weeks, and after 8 weeks, including subjective perception questionnaires, body composition analysis, and functional physical performance tests. The study aims to examine changes in physical status, functional capacity, and user experience during continuous product use.

Study Overview

• Status: Not yet recruiting
• Conditions: Healthy Volunteers
• Intervention / Treatment: Dietary supplement: Dairy intervention

Detailed Description

With increasing awareness of regular exercise and health promotion, sports nutrition products have become a common supplementation choice among physically active populations. In real-world settings, these products are typically consumed continuously as part of daily life. Evaluating changes in physical status, functional physical performance, and users' subjective perceptions during actual use therefore requires research designs that closely reflect everyday living conditions.

This study recruits physically active adults aged 18-39 years and conducts an 8-week intervention involving the consumption of a dairy product enriched with high protein, calcium, and vitamin D. A pre-, mid-, and post-intervention design is employed, integrating subjective perception questionnaires, body composition analysis, and functional physical performance assessments to evaluate changes in physical status, functional capacity, and subjective experiences throughout the intervention period. Through this multi-dimensional evaluation approach, the study aims to examine the practical feasibility and application value of the product in real-life settings and to provide evidence to support sports nutrition practice and future research.

• Study Type: Interventional
• Enrollment (Estimated): 50
• Phase: Not Applicable

Contacts and Locations

• Study Contact: Name: Yi-Ju Hsu; Phone Number: +886-3-328-3201 #2430; Email: ruby780202@ntsu.edu.tw

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: Adult
• Accepts Healthy Volunteers: Yes

Description

Inclusion Criteria:

• Aged 18-39 years.
• Have regular exercise habits, defined as exercising at least three times per week, with each session lasting no less than 30 minutes. Exercise intensity should reach a heart rate of approximately ≥130 beats/min or a perceived intensity characterized by noticeable breathlessness and sweating.
• Preferably, at least one exercise session per week should include resistance training.
• Participants must be able to consume dairy products and have no lactose intolerance.

Exclusion Criteria:

• Individuals with lactose intolerance or an allergy to dairy products.
• Individuals who are pregnant, planning to become pregnant, or breastfeeding.
• Individuals with a smoking habit.
• Individuals diagnosed by a physician with cardiovascular disease, hypertension, metabolic disease, asthma, or kidney disease.
• Individuals with a body mass index (BMI) ≥27.
• Individuals who have experienced limb or neuromuscular exercise-related injuries within the past 6 months that prevent them from engaging in regular exercise.

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Dairy intervention group; An 8-week high-protein, high-calcium, and vitamin D-enriched dairy intervention.	Dietary supplement: Dairy intervention; An 8-week high-protein, high-calcium, and vitamin D-enriched dairy intervention.

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Questionnaire-based subjective assessment	Participants' subjective physical sensations, post-exercise fatigue, body image perceptions, and product use experience will be assessed using individual items from a self-administered questionnaire developed for this study. Questionnaire items may include Likert-scale items, categorical response options, and open-ended responses. Likert-scale items will be reported separately according to their original response scale, with the minimum and maximum values specified for each item. Categorical items will be reported as the number and percentage of participants selecting each response option. Open-ended responses will be summarized descriptively. No overall questionnaire total score will be calculated.	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Handgrip Strength Test	Participants performed the test in a standing position with their arms naturally hanging down. They held the handgrip dynamometer with one hand and applied maximal force continuously for at least 3 seconds. Each hand was tested three times, and the best value was recorded.	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Push-Up Test	Participants performed the push-up test on an exercise mat, with both hands placed shoulder-width apart to support the body. The fingers pointed forward, the elbows were fully extended, and the feet were approximately 10 cm apart. Male participants performed the test with support from the feet, whereas female participants performed the modified version with support from the knees. Participants were instructed to complete as many repetitions as possible while maintaining proper form. The test was terminated when the movement no longer met the required standard or could not be continued.	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Curl-Up Test	Participants lay supine on an exercise mat with both knees bent and feet flat on the floor. They performed curl-ups according to a fixed rhythm. Participants were instructed to complete as many repetitions as possible while maintaining proper form. When a participant failed to perform the movement correctly once, the examiner raised one hand and indicated the number "one." If the participant failed a second time, the examiner indicated the number "two." The test was terminated when the participant failed twice or completed 75 repetitions. If the participant was unable to maintain the required rhythm or perform the movement according to the standard criteria, the test was stopped.	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Three-Minute Progressive Step-in-Place Test	Participants performed step-in-place movements according to the instructions and raised their knees to the designated height. The test lasted for 3 minutes, with an initial cadence of 96 beats per minute, which was progressively increased each minute. During the test, heart rate was recorded using a heart rate monitor before exercise, during exercise, and during the post-exercise recovery period.	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Body weight	Body weight will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported in kilograms (kg).	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Body mass index	Body mass index (BMI) will be calculated from body weight and height and reported in kilograms per square meter (kg/m^2).	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Body fat percentage	Body fat percentage will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported as a percentage (%).	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Fat mass	Fat mass will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported in kilograms (kg).	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Skeletal muscle mass	Skeletal muscle mass will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported in kilograms (kg).	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Skeletal muscle percentage	Skeletal muscle percentage will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported as a percentage (%).	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.
Waist-to-hip ratio	Waist-to-hip ratio will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported as a ratio.	The testing time points are set as follows: before the intervention, after 4 weeks of intervention, and after 8 weeks of intervention.

Collaborators and Investigators

• Sponsor: National Taiwan Sport University
• Investigators: Principal Investigator: Yi-Ju Hsu, Professor, National Taiwan Sport University

Study record dates

Study Major Dates

• Study Start (Estimated): June 1, 2026
• Primary Completion (Estimated): September 1, 2026
• Study Completion (Estimated): September 1, 2026

Study Registration Dates

• First Submitted: May 8, 2026
• First Submitted That Met QC Criteria: May 16, 2026
• First Posted (Actual): May 20, 2026

Study Record Updates

• Last Update Posted (Actual): May 20, 2026
• Last Update Submitted That Met QC Criteria: May 16, 2026
• Last Verified: May 1, 2026

More Information

Terms related to this study

• Other Study ID Numbers: NTSUIRB-115-010

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No