I agree with Sheila. Sounda like you have shin splints. I recommend going to a New Balance store. Check out their website.
www.newbalance.com - I just bought a pair last weekend (Cross Trainers) but they are highly recommended by my Physical Therapist. Good luck
Plan on spending good money for them and make sure you are doing the proper excersices to cool down your calves. I suffer from shin splints and it can be painful.
Hang in there.
