What are the benefits of having the sun on your back?
Sun exposure on the back can help absorb calcium and phosphorus in the intestines, regulate viscera, qi and blood, and warm the meridians.
Sunbathing on the back between 16 and 17 o'clock is the best time for the human body to store vitamin D. This time period is in the afternoon, the sun is going to set, the temperature is relatively warm, but the alpha beam in the sunlight's ultraviolet rays is stronger. The best time to store vitamin D is to spend more time in the sun to help absorb calcium and phosphorus in the intestines. The back of the human body is yang, and many meridians and acupuncture points are on the back. Sunbathing in the evening can help regulate the qi and blood of the organs and warm the meridians.
But when sunbathing, be sure to let the sun shine directly on your back, that is, just face your back towards the sun. You can rub your hands together and then rub the kidney acupoint on the back (the location is level with the navel and 1.5 inches away from the spine), which has the effect of warming the kidneys and boosting yang. If it is convenient, lift up your clothes and let the sun shine on these two acupuncture points, which can replenish kidney qi. Or when basking in the sun, rub your hands together to warm them and then rub the area together.
Extended information:
You must also follow principles when basking in the sun. When going outdoors to bask in the sun, choose a time when the light is not too strong. Especially in summer, be sure to avoid the scorching afternoon sun. It is best to do it around 10 or 11 o'clock in the morning, when the sunshine is relatively mild. Don't go out to bask in the sun on windy days to avoid getting cold. If you are at home, you can sit for a while with your back to the sun when the sun is shining on the balcony.
Old people can live longer if they are exposed to the sun on their backs, but it should be noted that they should not be exposed to the sun through glass, as this will have little effect. The time in the sun should not be too long, 20-30 minutes each time is appropriate.
People's Daily Online - Sunshine is a treasure, it is good for your health