Effects of Short-Term Resistance Training on Diaphragm Thickness, Hepatic Fat Density, and Quality of Life in Healthy Older Men

This randomized controlled trial investigated the effects of a four-week moderate-intensity resistance training program on diaphragm thickness, hepatic fat density, and health-related quality of life in healthy community-dwelling older men aged 60-75 years. Thirty participants were randomly assigned to a resistance training group or control group. Diaphragm thickness and hepatic attenuation were assessed using non-contrast computed tomography, and quality of life was evaluated using the SF-12 questionnaire. The primary outcome was change in diaphragm thickness. Secondary exploratory outcomes included hepatic fat density and SF-12 physical and mental health scores.

Inclusion Criteria: * Male * Age 60-75 years * Community-dwelling and functionally independent * No structured exercise program in past 6 months * No musculoskeletal injury in past 6 months * Ability to provide written informed consent * Stable neuropsychological status Exclusion Criteria: * Chronic liver disease * Uncontrolled cardiovascular or pulmonary disease * Recent respiratory infection * Use of medications affecting muscle or liver metabolism (e.g., systemic corticosteroids, anabolic agents, hepatotoxic drugs) * Participation in structured exercise or respiratory training within past 6 months * Unstable thyroid hormone replacement therapy