I get chronic shin splints too, even with all the help I can get from orthotics, physical therapists, and sports trainers. I had a (then undiagnosed) stress fracture in high school from sprinting and hurdling. My attempts to do some short distance running for fitness through college and graduate school has earned me a nice osteochondritis dissecans lesion in my right ankle. It hasn't healed in years of no to lo-impact rest, but I don't want to get the surgery for it. I cycle because my doctor told me to get on indoor bikes while I was supposedly "healing." I don't want to be stuck in a gym forever, but running is still out for me.