Sleep Duration and Disturbances Were Associated With Testosterone Level, Muscle Mass, and Muscle Strength--A Cross-Sectional Study in 1274 Older Men.

Abstract in brief

• The study found that sleep duration has an inverted U-shaped relationship with testosterone levels, muscle mass, and strength in older men, meaning moderate sleep is associated with optimal levels, while too little or too much sleep can decrease them.
• Sleep disturbances like prolonged sleep latency and insomnia are linked to lower muscle mass, weaker grip strength, and slower walking speed, highlighting the importance of good sleep quality for muscle health.
• Although earlier bed and wake times influence testosterone and muscle mass, sleep disturbances did not affect hormone levels directly, suggesting that both sleep duration and quality impact muscle function in older men.