Is 8.5 hours of sleep per day enough for a 10-year-old child?

Generally, 8.5 hours of sleep per day is usually insufficient for a 10-year-old child. It is recommended that they get about 10 hours of sleep daily.

A 10-year-old child is in a critical period of physical growth and development. During quality sleep, anabolic processes typically exceed catabolic ones, helping replenish energy expended during the day, relieve fatigue, and restore physical strength. Deep sleep also promotes the secretion of growth hormones, enhances protein synthesis, restores energy in nerve cells, supports the recovery of various bodily functions, and improves memory. Generally, around 10 hours of sleep helps promote healthy physical growth and development.

During this growth phase, it's important to strengthen nutrition by consuming more high-protein and high-vitamin foods, which can stimulate physical development.