Effects of a 12-Week Strength Training Program on Physical Function, Bone Health, Cognitive Function, and Quality of Life in Women Aged 65–74 Years

INTERVENTION: Behavioral : This study is a randomized controlled trial designed to evaluate the effects of a 12‐week machine‐based resistance exercise program in women aged 65–74 years. Participants will be randomly assigned to either an intervention group or a control group. Both groups will undergo the same baseline and post‐intervention assessments. The intervention group will participate in a supervised machine‐based resistance exercise program conducted at Iron Gym using seven weight‐training machines: chest press, lat pull‐down, shoulder press, biceps curl, leg press, leg extension, and leg curl. The exercise program has been developed according to the exercise prescription guidelines for older adults published by the American College of Sports Medicine (ACSM). Participants will complete the program three times per week for 12 weeks, with each session lasting approximately 50–60 minutes. Each exercise session will consist of a 5‐minute warm‐up, 40–50 minutes of resistance exercise, and a 5‐minute cool‐down. The resistance exercise program includes four upper‐body exercises (chest press, lat pull‐down, shoulder press, and biceps curl) and three lower‐body exercises (leg press, leg extension, and leg curl). To minimize fatigue and maximize exercise efficiency, upper‐ and lower‐body exercises will be performed alternately in the following order: chest press, leg press, lat pull‐down, leg extension, shoulder press, leg curl, and biceps curl. Each exercise will be performed for three sets of 12 repetitions with 60 seconds of rest between sets. Exercise intensity will be progressively increased throughout the intervention according to the principle of progressive overload. During Weeks 1–2 (adaptation phase), participants will exercise at 40–50% of their one‐repetition maximum (1RM) to promote familiarization with the equipment and neuromuscular adaptation. During Weeks 3–8 (progression phase), intensity will be increased to 50–70% of 1RM to improve muscular strength and endurance. During Weeks 9–12 (strengthening phase), intensity will be further increased to 70–80% of 1RM to maximize strength development. Exercise intensity will be monitored using the Borg Rating of Perceived Exertion (RPE; 6–20 scale) and periodic submaximal 1RM assessments. If a participant successfully completes more than 12 repetitions with proper technique for two consecutive sessions, the training load will be increased by approximately 5–10%. All exercise sessions will be supervised by qualified exercise professionals, and participants will receive continuous instruction on correct exercise technique, breathing, and safety procedures. The control group will not receive any structured exercise intervention during the study period. Participants assigned to the control group will be instructed to maintain their usual daily activities and lifestyle and to refrain from initiating any new structured resistance exercise or regular exercise programs throughout the 12‐week study period. They will undergo the same assessments as the intervention group at baseline and after 12 weeks. The CONDITION: Not Applicable PRIMARY OUTCOME: Fall‐related physical function (30‐Second Chair Stand Test, 30‐Second Arm Curl Test, Grip Strength, Chair Sit‐and‐Reach Test, Back Scratch Test, 8‐Foot Up‐and‐Go Test, One‐Leg Standing Test) SECONDARY OUTCOME: Bone mineral density (lumbar spine L1–L4, femoral neck, and total femur) Cognitive function assessed by the Korean Montreal Cognitive Assessment (K‐MoCA) Health‐related quality of life assessed by HINT‐8 Serum irisin, brain‐derived neurotrophic factor (BDNF),insulin‐like growth factor‐1 (IGF‐1) level INCLUSION CRITERIA: Women aged 65–74 years. No participation in any structured or regular exercise program within the previous 3 months. Medically and physically able to participate in a resistance exercise program. Able to understand the study procedures and willing to provide written informed consent.