I am spinning 1 hr 2X/week, pilates same, gentle yoga same, also in a progressive walking program designed by Reebok that takes me from walking 14 total weekly mileage(now) to 40 miles and then ramps down quickly to 9 miles the last week before the AVON39 in NYC, middle of October. What are shin splints, how can I tell if I get them, how do I treat them, and lastly, how can I avoid them?