A visit to an allopathic dermatologist is required to find out that the cause of the itching. There can be many conditions associated with the sweat glands that cause this symptom(for e.g.prickly heat etc). Only when we know why this is happening can a treatment be formulated for you. So visit a dermatologist near you. Also please read this link before you choose your dermatologist http://www.skinmatra.com/single-post/2016/07/03/Skin-Troubles-Here-is-WHAT-NOT-TO-DO

Greetings. Is this a new symptom o feature that you have noticed or have you always suffered from this? Your symptoms are suggestive of something called exercise induced urticaria / cholinergic urticaria. Some people sweat and develop itching and wheals during a cholinergic response of the body. You should see a qualified dermatologist near you and get evaluated for the same. You may require symptomatic treatment with anti histamines.

Thanks for the query. If you are getting itching involving most of the body especially with a rash (hives) on regular basis on exertion then it is most like to be a form of allergic skin condition called " Cholinergic urticaria". This condition is caused by sweating. Common triggers include running/ jogging, hot bath, fever, emotional stress.