Are you properly protecting your skin from ultraviolet (UV) radiation while running? Aren’t you the one who thinks that sunscreen comes off with sweat anyway so there’s no point putting it on? Be careful! Even when it is cloudy or you are in the shade or inside the building, the UV rays are there and damage your skin.
Effects on the Skin
UV rays, which are constantly reaching the Earth’s surface and causing damage to the skin, include UV-A and UV-B types. Normally, the skin prevents UV rays from penetrating it thanks to stratum corneum or epidermis reflecting and scattering the radiation, as well as with the melanin pigment. However, overexposure or long-term exposure to the UV rays cause sunburn and damage the skin in various ways.
What is UV-A?
30 to 50 percent of UV-A rays penetrates deep into the skin through epidermis. You are constantly but unknowingly exposed to them during the day, and their cumulative effect appears over time. Because of such effect, UV-A is also called “Daily UV”. Soon after being exposed to UV-A rays (for approx. 20 minutes on a summer day), the skin turns dark temporarily, and if exposed further, for about one hour, such darkening (“tanning”) increases and persists on the skin. If you are constantly exposed to UV-A rays for a long term, dermal fibroblasts and collagens will be damaged, resulting in wrinkles and sagging.
What is UV-B?
On the other hand, UV-B rays are mostly scattered and absorbed by the epidermis and cause abrupt and severe damage to the skin. UV-B is also called “Leisure UV” because you are more likely exposed to it while doing leisure activities and outdoor sports such as running, bathing or skiing. Within a few hours of exposure, the skin turns red and gets inflamed with stinging pain – this is what we call “sunburn”. After a while, the pigment cells create melanin. If you are exposed to UV-B rays for a long term, the skin gets inflamed and the skin cells are damaged resulting in spots, wrinkles and sagging.
How to protect your skin from UV rays
The best way to protect your skin is to prevent the skin from UV rays exposure. By taking various measures to protect the skin from direct sunlight, the damage can be alleviated. Sun-protective clothing is effective, while sunscreen and UV-protection emulsion are also very helpful. Foundation also plays an important role in shielding the skin from UV rays.
How to select the best UV care product
It is important to select the right sunscreen according to the strength of UV rays, the area, the hours of exposure, and time of the day.
Sunscreens include sun block, UV-protection emulsion, makeup base, foundation, etc. Check the sun protection factor shown on the product to choose the right item.
What are SPF and PA ?
SPF (＝Sun Protection Factor)
Sun protection factor against UV-B is shown as SPFXXX. The higher the number in XXX is, the more effective the item is to protect the skin from UV-B. (The max number is 50+)
PA (＝Protection Grade of UVA)
PA is a grade to indicate the effect of protecting the skin from UV-A with a scale of + (one plus) to ++++ (four plus), and the more + marks, the more effective the product is in protecting against UV-A.
- Select sun protection cosmetics (sun block cosmetics) by referring to SPF and PA, while taking into account the strength of UV in the area, the hours of exposure, etc.
- Spread the sunscreen on your skin thoroughly and evenly, and reapply whenever you sweat to ensure protection!
Refer to Shiseido Bi no Lab (Japanese only)
This information is based on the skin research conducted by Shiseido in Japan.