Occasional itching is a normal, common experience. Just like a red face during exercise, itchy legs are no cause for alarm, that is unless the itch is accompanied by hives. Exercise-induced urticaria is in a sense an allergy to exercise, and if you're also experiencing stomach cramps, swelling of the face or tongue, or difficulty breathing, seek medical attention immediately. Sometimes, though, it can result from a specific stimuli, such as allergies, environmental factors like the ones listed below.
If your body starts itching when you exercise consider the following possible reasons:
1. Inconsistent exercise. Keep exercising to allow the body to adapt.
Runners itch also seems to be more common in those who are getting back in shape. If you’ve taken some time off of running and are just getting back into it, you may also experience uncomfortable welts or rashes. As your heart rate increases, blood flows faster, and the millions of tiny capillaries and arteries in your muscles begin to expand rapidly. The capillaries stay open to allow for maximum blood passage when you're fit, but if you're out of shape, your capillaries tend to collapse, not allowing as much blood to pass through. When your capillaries expand, the surrounding nerves become stimulated and send messages to the brain, which reads the sensation as itching. So if you want to prevent itchy legs, keep up with your regular exercise routine.
2. Showering too often. Try dry brushing daily and shaving your legs...even in the winter.
Shower less, skin brush & use natural oils/lotion. Ladies, watch out if you happen to shower more than once a day. Too many showers can wash away some of the skin’s natural oils that keep it moist, leaving your skin dry and itchy. This is something to consider for women is non-shaved legs. A lot of women don’t shave their legs in the winter, but that “stubble” can cause itching—especially when wearing running tights,
Skin brushing helps move lymph fluid into the lymph nodes so this waste can then be eliminated. Dry skin brushing boosts circulation, delivering oxygenated blood to the skin and other organs, which helps them do their jobs better. Dry skin brushing should be done daily for best results, or even twice a day if you like.
3. Producing too much histamine. Try taking an antihistamine before working out to see if the itch stops.
Histamine is a known vasodilator; it increases blood flow to injured or infected tissues to help the immune system get at the problem area. And one Japanese study showed that histamine may be released during exercise to help protect the body against exercise-induced fatigue or exhaustion.
Unfortunately, histamine also sends itch signals to the brain, which means an increase histamine production in your body could induce general feelings of itchiness, which seems to be what you’re experiencing. (For more on how histamine induces itch, check out this study.)
4. Maybe it's your laundry detergent.
Laundry detergent. Some fabrics can also irritate the skin and wick away moisture, leaving the skin even dryer. Laundry detergent may also be the culprit. Opt for sensitive skin detergent to avoid any irritation.