The difference between drying your stomach and drying your back.

Different degrees of skin exposure will produce different physiological effects.

1. When drying the stomach, the skin on the abdomen will be completely exposed to the sun, while when drying the back, the skin on the back will be completely exposed to the sun.

2. Dry back can activate immune cells under the skin of the back, which contributes to the absorption and synthesis of calcium. Moreover, drying the stomach helps to dispel the cold in the stomach and improve the digestive function.