Tempo and Threshold Runs

What the effort is

Threshold effort is the pace you could hold for about an hour in a race. Coaches use "tempo" and "threshold" loosely, and both mean running at or a little under that effort: comfortably hard, controlled discomfort. Train slightly below it, at it and slightly above it, and treat it as one part of a plan, not the whole of fitness.

This is aerobic work at the hard end. It sits on top of a base of easy running and does not replace it: threshold sessions are a tool you add on top of easy running, and not the base of your training.

Pace it by effort

Speech is the check: at threshold effort you can no longer talk comfortably (see the guide on the talk test). Most runners run their threshold work too hard, and a session that turns into a race has left the zone it was meant for.

Time at the effort is the point, so the exact pace matters less. If the session is going badly, cut the pace or the length by 5 to 10 percent instead of grinding through it. Heat, wind and hills move the pace, so hold the effort and let the pace go where it goes. Your body does not know the difference between a mile at 4:55 and a mile at 5:05, only the effort.

Shapes of a session

Warm up and cool down with easy running. The minutes below are the work only. Three shapes cover most of it:

• Continuous: one steady block at threshold effort.
• Cruise intervals: 6 x 5 minutes, 3 x 10 minutes or 10 x 3 minutes with 1 to 2 minutes of jogging between. The short breaks let your heart rate come down, and they add up to more time at the effort than one block would give you.
• A progression run that starts at marathon pace and finishes down in the threshold zone. See the guide on progression runs.

How long and how often

Start with 15 minutes of work in total and build to 25 to 30 minutes. If you have only run easy so far, start with 5 minutes on and 3 minutes of easy jogging, repeated, and add to it. A half marathoner can build to 40 to 45 minutes in the top weeks, run as 15-minute blocks with 1 to 2 minutes between, and does not start there. Eight miles of threshold in one session is far too much for a recreational half marathoner.

Once a week is enough for most runners. Some handle two in a week, or three in two weeks, and more than that risks overtraining and injury. A threshold session is a hard session: count it in your two a week, and never put it next to another hard workout. For how a week fits together, see the guide on periodization.

Where it fits by race

The place of threshold work changes with the race:

• Half marathon: the first hard block. After a base of 4 to 8 weeks of easy running, do threshold work for 4 to 6 weeks, then add half-marathon-pace work. See the guide on half marathon training.
• Marathon: a supporting session. The order of importance is the long run, then marathon-pace running, then threshold work, then faster intervals, and easy volume comes before all of them. See the guide on marathon training.
• 5K and 10K: one session a week just under threshold is the aerobic hard session, and short faster reps are the other. That is about two aerobic sessions to one faster session, cycled across two-week blocks. See the guide on 5K and 10K training.