Cause: Sweating helps the body stay cool, so it's normal for runners to sweat when they run. But hyperhidrosis, or profuse sweating, occurs when the body's normal cooling operations malfunction. Those with hyperhidrosis appear to have overactive sweat glands.
Prevention: Try using a clinical-strength antiperspirant. You don't need a prescription for it -– a product such as Secret Clinical Strength Waterproof Deodorant is available over-the-counter at drugstores. Apply it before you go to bed, so your body can absorb it overnight, and then reapply before your run. You may also want to use the antiperspirant on your feet, since heavy sweaters are prone to foot blisters. In extreme cases, medication or surgery may be necessary.
