Just a note in reference to the recurrant shinsplints and if it harms your training to rest:
Its not really a question of if it harms your training, shinsplints wont go away unless you rest them. By all means take up other forms of exercise to keep your cardiovascular side up, things like rowing, swimming, cycling and also keep your mobility up with stretching and etc but in terms of repair, I'm sure no one needs to explain what shin splints are so I wont bore you with the description, its pain due to injury. If you don't rest, you wont be able to repair and worse, the tear will get worse, it gets worse and it not only takes longer to repair, it also can risk becoming much worse and becoming something which causes a great deal more pain. Please please rest!
When you have recovered enough to not feel immediate pain when pressing on the area, I'd suggest going for a sports massage for your calves, (posterior rather then on the area which is in recovery!) just to help boost the recovery (just because you can press on the injury and not feel pain it doesn't mean the injury has gone). Its then another few weeks and your in a better place to start again.
If you feel ANY pain when restarting stop STRAIGHT AWAY and rest and repeat the above until your back on track and again, if it comes back repeat but take longer. It will take a long time because your legs don't get the same circulation as other organs more central to your torso which is why its so important to keep the circulation going and also to make sure your nutrition is adequate. Proteins basicly (meat, fish, eggs, dairy, if your a veggie then don't forget to eat complete proteins, nuts are an incomplete protein and need to be eaten with pulses which are also incomplete but when eaten together form a complete protein, google complete proteins for more info). But rest is really the only thing that works for shinsplints. Its not easy and can feel like forever but it does pay off and being able to run pain free at the end of it, you'll thank yourself trust me!