I got stress fractures in my shins before. They were chronic posterior shin splints (on the inside) that just got worse and worse because I couldn't stop training. Eventually they became stress fractures and they throbbed and hurt all the time, not just while I was training. At this point I decided to go get x rays done because they were killing me all the time.
Here are some things the trainer told me that may be helpful....
1) They said to rest for 3-4 weeks and ice, ice, ice every day. They said shin splints aren't something you can work through, they only get worse and then you end up in more pain so you're better off to take a few weeks and just rest them.
2) Always wear good shoes with lots of cushioning and good arch support. Besides overuse, I also overpronate (that's when your foot turns slightly in when you walk or run) This was so slight that I had never even noticed it before, but it can be a cause of shin problems. A running shoe shop can match you up with shoes that fit your particular foot mechanics, it really makes a HUGE difference, especially if you supplement your training with cardio, or do any kind of walking/running (even walking around campus or standing on your feet at work). They will actually have you bring in an old pair of shoes to determine your wear pattern. I never trust those Foot Locker-type places at the mall, the people who work there usually don't know much about footwear, they are just retail clerks, not athletes themselves.
3) They said to start every workout, whether cardio or strength training, with 5-10 minutes of gentle warm up, like walking on the treadmill, followed by stretching just to get the muscles warm and loose so they are not shocked by a heavy workout. I also stop several times during the workout to stretch. There are stretching tips available online if you do a search in google for "shin splints stretches"
4) The trainer gave me some exercises to start doing a few months before the next season began. They actually helped me avoid the dreaded shin splints for 3/4 of the season, and when I did get them they weren't as bad.
Lying on your back with legs in the air do 3 sets of the following 3x a day.:
a) point both toes and then flex them as far as possible (15 reps)
b) now alternate (one foot is felxed while the other is pointed- 15 reps)
c) circle both ankles around together, using the full range of motion (15 reps then switch directions and do 15 more)
These sound easy, but if you do them correctly you really feel the burn. If your shins are really killing you now I would just rest & ice for a couple of weeks before you start doing the excercises.
They told me that other causes for shin problems can be a muscle imbalance (calves too strong in relation to shin muscles), and training to much to soon, like if you have been out of the gym for a while and then go "full steam ahead" instead of easing into your old schedule.
If you like mountain biking, that might be a good way to keep your legs in shape while you are resting up your shins. Good luck, remember to ice a lot.
