From the Coach guide
A comfortably hard, steady pace that you hold for a set time.
Tempo runs train you to hold a hard pace for longer. They raise the pace you can keep before you tire quickly.
Warm up easy first. Then run comfortably hard: you can say a few words, but not full sentences. Keep the pace steady.
About the pace you can hold for 1 hour. Some plans call this threshold pace. Your threshold test measures it.
Tempo runs build the pace you can hold in a race. Tempo intervals and cruise intervals train the same pace in parts.
Threshold test: run all out for 30 min, to measure this pace. Intervals: shorter, harder repeats with rest between.
8-week randomized trial; 40 moderately trained men
4 × 4 min intervals at 90–95% of max heart rate raised VO₂ max more than threshold running or easy running that did the same total work.
The study was small and short, and all the runners were young men. Threshold running still has other uses, such as race pace.
Coach