For as long as I can remember, my legs will start to itch when I begin jogging. Sometimes the itching is unbearable and I have to stop. I noticed that it doesn't happen during sprinting / high intensity interval work. Is there a reason for this?
Itching/tingling indicates an increase in bloodflow due to expanded capillaries and arteries. This problem should go away as you increase your level of physical fitness. If the itching comes with a rash though, it's more likely to be exercise-induced anaphylaxis (an allergic reaction).