Overtraining is the biggest problem incurred by runners who lack the experience or discipline to cope with their own enthusiasm.
Happy people don't run a 3:47 mile.
You've got to be a little bored to be doing really good training.
There are no secrets to running success,anyone who says there are is probably trying to sell you something.
Road racing is rock 'n roll; track is Carnegie Hall.
Run your own race at an even pace. Consider the course, the temperature, the weather, and most importantly, your current level of fitness.