The authors looked at injury patterns in several sports, and concluded that undertraining puts athletes at just as much risk as overdoing it – while training hard can ultimately serve as a ‘vaccine’ against injury.
Yes, overtraining can cause injuries,” “But if you progressively find your way to higher training loads, it can actually protect you.”
“Beginners ramp up too fast,” “whereas experienced runners are so scared of overtraining, they often fail to get to a level they could probably handle.” Here’s how to achieve the perfect balance of workouts, depending on your primary goal.
http://www.runnersworld.co.za/training/find-your-training-sweet-spot/?