Feeling discomfort while exercising is not uncommon. Such discomforts include fatigue, sore muscles, excess thirst and, under certain conditions, nausea or vertigo. In some cases, though, exercisers may experience the weird sensation of itchy skin, which is sometimes accompanied with a rash. Itchy skin has several causes and isn't a life-threatening problem. If you experience itchiness that lasts for more than 24 hours or severe pain, consult a physician.
Hives
Exercising may induce hives that may be both itchy and painful. The University of Oregon states that hives can be caused by garments that repeatedly stroke or rub the skin. They can also occur from cold water, cold air, heat and sunlight. In severe cases of hives induced by exercise, respiratory obstruction or passing out may occur. If you feel faint or have difficulty breathing while exercising, stop and consult a physician.
Running Outside
If you run outdoors often -- especially in parks or through wooded areas -- your itchy skin may be caused by a naturally-occurring irritant like poison ivy, poison oak, poison sumac, dander or bug bites. This type of itchy skin can be treated with over-the-counter medications, including lotions, creams and pain relievers. Additional physical activity can exacerbate the itchiness, so engage in only mild exercise while recovering.
Cold Weather
Running in cold, dry weather can cause skin to chap, blister and dry out. This, in turn, leads to itchy skin that may even be painful to the touch. If you suspect chapped, dry skin is the source of your itchiness, switch to long-sleeved shirts and pants while running. If possible, run indoors until it begins to warm up outside and apply lotion to skin throughout the day.
Sweat
Exercise makes the body sweat more. The perspiration is then absorbed by clothing and, if not washed away, dries on the skin. This, in turn, can cause uncomfortable itchiness. Shower immediately after working out to rinse away sweat and dirt that accumulates on the body during exercise.
