Concept
Threshold pace
A controlled high aerobic pace near the limit of sustainable steady effort, commonly used to improve endurance at harder intensities.
What it should feel like
The effort is demanding but controlled. It is slower than an all-out short race and should not deteriorate immediately.
Tempo and threshold
Threshold describes an intensity. Tempo run often describes a continuous workout format, but the word tempo is used differently across coaching systems.
Why duration matters
The appropriate pace depends on how long the work interval lasts. Longer continuous work generally requires a slightly slower pace.
Use a realistic range and stop or adjust when the intended controlled effort becomes an uncontrolled race effort.
Threshold pace is not a single permanent number, and every run that feels hard is not threshold training.