When you go for a jog, if you feel an itchy sensation in the legs either during the jog or later, it could mean that something isn't right.
But sometimes, the reasons could be minor ones but in some cases the reason could be a serious one too and may need medical attention.
When the reason is a minor one then the itchy feeling goes away on its own in a coupe of days. But if the problem is due to serious circulatory disorders, then you may need to visit a doctor.
Try to take certain measures like warming up properly before exercising in order to raise the heat gradually, breathe deeply while you jog in order to ensure a steady blood flow, wear breathable clothes and ensure that you visit a doctor soon.
If you are new to working out, it is common to feel the itchy sensation due to the dilation of blood vessels. Also, exercise tends to stimulate the nerves and this could cause the feeling but gradually as your body adapts to the new activities, the itchy sensation goes.
If you have sensitive skin, anything from your soap to the fabric you wore could be the reason behind the itching sensation while running.
It could also be peripheral artery disease. Consult a doctor. When the blood circulation to the legs isn't proper during running, it could also cause tingling sensation.
Even dehydration could cause the itchy feeling. Dry weather could be the reason. Use a moisturizer to keep your skin moist.
When you go for running when the weather is too cold outside then the itchy sensation could be due to the sudden blood flow.
Friction between the skin and the fabric could also cause itching sensation. It could also cause a rash.
If you experience other symptoms like tightness in the chest, breathlessness, nausea along with itchy sensation in legs, then visit a doctor immediately as it could also be something serious too.