Run your own race at an even pace. Consider the course, the temperature, the weather, and most importantly, your current level of fitness.
There's no satisfaction without a struggle first.
Road racing is rock 'n roll; track is Carnegie Hall.
You've got to be a little bored to be doing really good training.
Overtraining is the biggest problem incurred by runners who lack the experience or discipline to cope with their own enthusiasm.
The endurance athlete is the ultimate realist.