Ask ten runners what a tempo run is and you will get ten answers, most of them “a bit fast”. That vagueness is why so many people run their tempo sessions too hard and get nothing out of them. Here is what the session actually is and how to pace it.
What a tempo run is
A tempo run is a sustained effort at roughly your lactate threshold — the hardest pace you can hold in a steady state, where your body is clearing lactate about as fast as it produces it. Go slightly faster and lactate accumulates, the effort spirals, and you are forced to slow down. Sit right at that line and you are training the single most trainable quality in distance running.
The everyday description is comfortably hard. That phrase sounds useless until you have run one properly, and then it is exactly right: uncomfortable but controlled, sustainable, and nowhere near a sprint.
Finding the pace without a lab
You do not need lactate testing. Three practical methods, in order of usefulness:
1. The talk test
At threshold you can say a short sentence — five or six words — and then need to breathe. If you can chat comfortably, you are too slow. If you can only manage single words, you are too fast. This is the most reliable field method there is, and it costs nothing.
2. Race pace
Threshold sits close to the pace you could race for about an hour. For a reasonably trained runner that is somewhere around 10 mile to half marathon pace. For someone newer to running, whose half marathon takes well over two hours, it is closer to 10K pace. Use whichever of your recent race times sits nearest the one-hour mark.
3. Effort out of ten
About 7 or 8 out of 10. Easy running is 3 to 4. A 5K race is 9. If your tempo run feels like a 9, you have run a race, not a session — and you will pay for it in the days after.
Three formats that work
The classic tempo
Warm up 10–15 minutes easy, run 20 minutes continuously at threshold, cool down 10 minutes. This is the standard for a reason. Twenty minutes is long enough to matter and short enough that pacing errors do not ruin the whole session.
Cruise intervals
Warm up, then 3 × 8 minutes at threshold with 90 seconds easy jogging between. The short breaks let you hold the correct pace for more total time than you could continuously, which makes this the easier way in for most people. It is also more forgiving if you misjudge the first rep.
Progression run
Run 40 minutes, starting easy and finishing the last 10–15 minutes at threshold. Useful late in a marathon build, because it teaches you to find that gear on tired legs — which is exactly what a race asks of you.
The mistakes almost everyone makes
- Running it too fast. By far the most common. A tempo run that turns into a time trial gives you the fatigue of a race with none of the benefit, and it compromises the next few days of training.
- Starting too quick. The first two minutes always feel easy. Hold back — if the last five minutes are falling apart, the first five were wrong.
- Doing them too often. One threshold session a week is plenty for most amateurs; two only if the rest of the week is genuinely easy.
- Not running easy on the other days. Tempo work only pays off if the surrounding days are slow enough to let you absorb it. Running everything at a medium pace is how people plateau for years.
Where it fits in a week
One tempo session, one long run, and the rest easy is a solid week for most amateur runners. Keep at least two easy days between the tempo and the long run. In the last ten days before a race, keep the session but cut the volume — sharpness without the fatigue.
Tempo runs are one member of a wider family of threshold work. For the physiology behind them, and how they differ from intervals, read the guide on threshold training.