What is a tempo run? A plain-English guide

What 'comfortably hard' actually means

Tempo is one of those runner words that sounds more technical than it is. It describes a sustained run — one continuous block, not repeated bursts — at an effort between easy and racing. Taper calls this effort comfortably hard · short phrases only.

An easy run is conversational: you can chat in full sentences. A tempo run is the next step up. Your breathing is deeper, talking is reduced to a few words, but you are not gasping or counting down the seconds.

• Right effort: breathing steady and deep, you can say a short sentence, and you feel in control.
• Too hard: you can only manage one word, you are counting down, or your stride is getting scrappy.
• Too easy: you could chat comfortably for the whole block. That is an easy run — still useful, just not tempo.

The pace is personal. Weather, sleep and hills all change it. Use effort first: if you could hold it for about an hour on a good day, you are in the right place. If you are slowing sharply or your form is falling apart, ease back.

Why runners do them

Tempo runs train your lactate threshold — the point where fatigue starts to build faster than your body can clear it. You do not need the science to benefit. By spending time at a controlled, hard-ish effort, you teach your body to hold a quicker pace for longer. The effort that used to feel hard starts to feel more manageable.

They are also a useful bridge between easy running and faster work. If you are new to speed, tempo is often a calmer first step than intervals, which are short, hard bursts with recovery jogs in between. Tempo is one sustained block; intervals are repeats.

How to run your first tempo

Start with a proper warm-up: 10–15 minutes of easy running, then a couple of short, gentle speed-ups if you feel stiff. The tempo block itself can be short. For a first go, 10–15 minutes at comfortably hard is plenty. More experienced runners might hold 20–40 minutes, or split it into two blocks with a short easy jog between.

Finish with 5–10 minutes of easy running to cool down. A simple session might look like: 15 minutes easy, 15 minutes comfortably hard, 10 minutes easy. That is it. No need to chase an exact pace on your watch; learn the feel first.

If you are following a plan, tempo usually appears once a week, not every run. The rest of your week should stay easy — that is what lets you recover and adapt. If you are just starting out, our guide to starting running is a better first step than adding speed straight away.

Common tempo mistakes

• Going too fast. Tempo is not a race. If you cannot speak two or three words, you have crossed into interval effort; ease off.
• Holding it too long. A long tempo can leave you flat for days. Build the block gradually and keep most of your running easy.
• Skipping the warm-up. Starting hard from cold makes the session feel worse and your form scrappier. Easy minutes first.
• Treating it as a test. One bad tempo does not mean fitness has gone. Sleep, heat and stress all show up in your pace.

If pain changes how you run, stop and see a GP or physio. Tempo should feel hard, not sharp or wrong.