Often when i run my feet go numb (the shoes are not the problem). usually begins 30 minutes in after noticing tight calves/achilles. is that unusual/bad?

See below: Having these types of symptoms can best be solved by having your doctor perform a thorough evaluation. Only through this type of process can he/she discover what's going on and how best to help you.

ECS?: This sounds like it may be exertional compartment syndrome. In short the tissues of your legs may not be getting enough oxygen. This affects the nerves by causing numbness. Treatment consists of releasing the compartments. Minimally invasive treatment is available. Get a diagnosis, then decide on treatment. An orthopaedic foot and ankle surgeon can help you. www.orthodoc.aaos.org/footankle.