Endurance training runs at a few named paces, and threshold, tempo and easy are the three most runners need. Threshold pace is comfortably hard, the pace you could hold for about an hour; tempo is close to it; easy is the conversational base pace. Setting each from a recent race, rather than guessing, is what makes a training plan actually work.
What threshold pace is
Threshold pace, or threshold running, is the effort at which lactate begins to accumulate faster than the body clears it, roughly the pace you could race for an hour. What is threshold pace in practice is comfortably hard: sustainable but demanding, and training at it raises the speed you can hold before fatigue sets in, which is why it is the backbone of most distance plans.
Tempo and easy pace
Tempo run pace sits at or just below threshold, a sustained hard effort for a set time, while easy run pace is the conversational base that most weekly volume should be. The two do different jobs: tempo sharpens the threshold, easy builds the aerobic base and allows recovery, and confusing them, running easy days too hard, is the most common training mistake.
Setting the paces from a race
Threshold, tempo and easy pace are all derived from a recent race time through the same VDOT-style tables that predict finishes. That is the honest way to set them: a race is a measured effort, so the paces that follow are matched to your current fitness rather than to how you feel on the day, which is what keeps the easy days easy and the hard days hard.
Questions people ask about threshold pace
What is threshold pace?
It is the comfortably hard effort you could race for about an hour, where lactate starts to accumulate faster than it clears; training at it raises the pace you can sustain.
How is tempo pace different from threshold?
Tempo pace sits at or just below threshold as a sustained hard effort, while threshold is the specific lactate-turnpoint pace; the two are close and often used interchangeably.
How do I find my easy run pace?
Derive it from a recent race through VDOT-style tables; easy pace should be conversational, and running it too hard is the most common training error.