Development and Strategic Research of Practical Applications in Sports Nutrition

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.

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.

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.

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.

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.

Body weight will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported in kilograms (kg).

Body mass index (BMI) will be calculated from body weight and height and reported in kilograms per square meter (kg/m^2).

Body fat percentage will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported as a percentage (%).

Fat mass will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported in kilograms (kg).

Skeletal muscle mass will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported in kilograms (kg).

Skeletal muscle percentage will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported as a percentage (%).

Waist-to-hip ratio will be measured using the InBody 570 bioelectrical impedance analyzer (InBody, Seoul, South Korea) and reported as a ratio.