Physical exercise is often associated with increased skin coloration in light-skinned people.
In most contexts, working out is associated with being “red in the face,” especially when short, intense bursts of activity are involved. Nevertheless, under certain conditions and in the right environment exercise can have the opposite effect on your complexion. Your face can turn white after exercise because of a harmless cause — such as your blood supply redirects to your muscles — or the more serious issue of anemia.
Blood Supply Redistribution
The most common reason your skin turns white while you’re exercising is that much of your blood supply redirects to your muscles. Blood that normally flows through the small vessels close to your skin’s outer layers is instead pumped through the muscles to meet their increased oxygen needs. This effect is known as shunting. It’s more common in cold weather, when your body doesn’t need to send as much blood to your body’s surface to release extra heat, and when you are exercising at a high intensity, which maximizes the shunting effect.
Iron Deficiency or Anemia
Many exercisers become deficient in iron stored in their body. Iron carries oxygen throughout the body, and your body also needs iron to make hemoglobin, according to MedlinePlus. Hemoglobin is the portion of red blood cells (RBCs) that binds with oxygen and allows the RBCs to carry oxygen to working muscles.
Runners and other endurance athletes are especially susceptible to anemia because of iron lost through sweating and — in runners and joggers — as a result of mechanical impact stresses. Besides pale skin, anemia symptoms include fatigue, irritability, and a general feeling of being unwell. Oral iron supplements, as recommended by your physician, may be necessary to restore iron levels to their normal values.
Vitamin B12–Deficiency Anemia
Low iron is not the only nutrient deficiency that can wreak havoc on your RBCs. The National Heart, Lung, and Blood Institute reports that low levels of vitamin B-12 can cause vitamin B12–deficiency anemia or pernicious anemia. The symptoms of vitamin B12 deficiency resemble those of iron-deficiency anemia, with white skin, dizziness, fatigue, and shortness of breath usually present.
If allowed to persist, vitamin B12–deficiency anemia can cause bleeding, infections, and permanent brain or nerve problems. Treatments include the addition of foods rich in vitamin B12 and oral B12 supplements. In more severe cases, repeated injections of the vitamin are necessary.
Cold-Induced Skin Damage
Exposure to cold or blustery weather can cause frostbite or cold-induced skin damage that makes the skin look white. According to Kaiser Permanente, “frostnip” features numb or blue-white skin. Frostbite, cold injuries like trench foot and chilblains, and hypothermia can also cause pale or grayish skin color.
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