Running pace: how to find the right one for you

You head out for a run, your watch shows a pace, and you wonder if you are going too fast or too slow. The answer is not in a "pace by level" chart. It depends on what you want that day: an easy run, a race pace, a fast workout.

The good news: you don't need a lab or a complicated formula. A few simple benchmarks are enough to set your pace workout by workout, as long as you know their limits.

Pace, speed and min/km: the basics

Pace is the time it takes you to cover one kilometer: divide your total time by the distance. Example: 10 km (6.2 mi) in 55 minutes is 55 ÷ 10 = 5.5 minutes per kilometer, or 5:30/km (about 8:51/mi).

Speed says the same thing in reverse, in kilometers per hour: 60 ÷ 5.5 ≈ 10.9 km/h (about 6.8 mph). The speed and pace converter does the math for you.

This calculation tells you what you ran, not the pace you should run. A 5:30/km can feel very easy for one runner and be at the limit for another. Each workout has its own pace, depending on its goal.

Easy pace: the talk test

For an easy run, the simplest check is the talk test: you should be able to speak in full sentences without gasping after every three words. If you cannot, you are going too fast for an easy run.

A 2008 study concluded that the last stage where people can still talk comfortably matches the ventilatory threshold, the point where breathing speeds up sharply. A 2020 study of 20 cardiac patients on bikes found a looser link (correlations of 0.37 to 0.60) and large differences from one person to another. The studies give a rough guide, not an exact measurement, and the 2020 study did not involve runners. In practice, coaches use the talk test as a safety check: if you cannot talk, slow down.

What about health?

The WHO defines intensity by how it feels, on an effort scale from 0 to 10: moderate at 5-6, vigorous at 7-8.

Your race pace: start from a recent result

To work out what pace to aim for in a race, the most reliable starting point is a recent result over a similar distance: a timed 10 km (6.2 mi), or a race from this season. Riegel's formula, the most widely used, estimates your time over one distance from your time over another.

It has a known limit. In a 2016 study of amateur endurance runners (Vickers and Vertosick), the formula was well calibrated up to the half marathon, but it clearly underestimated marathon times, predicting times that were too fast: the predicted time was at least 10 minutes too fast for half of the runners. Models based on one or two previous races predicted better.

In practice:

• For a 10 km (6.2 mi) or a half marathon (13.1 mi), a recent result over a nearby distance gives you a good base.
• For a marathon (26.2 mi), do not convert a 10 km time mechanically. Leave a margin, especially if you have never run that distance.

The same study found that tempo runs, at a hard but sustainable pace, were more closely linked to race speed over shorter distances. To set your paces for a target race, the pace calculator and the split times tool give you benchmarks kilometer by kilometer.

Your level is already in your workouts

A 2020 study estimated critical speed, the highest intensity at which your body can stay in a steady state, from raw training data of more than 25,000 runners before big-city marathons. That estimate predicted marathon performance and pace: your recent runs already say a lot about your real level.

When your pace should change: heat and hills

Even with the right starting pace, conditions change things.

Heat. In one study, runners did a 10 km (6.2 mi) on a treadmill at their own pace, once at 25 °C and once at 35 °C. At 35 °C, they ran noticeably slower and rated the effort as harder, even though their average heart rate was similar. The participants were natives of tropical countries. Keep two things in mind: on hot days, a slower pace is normal, and heart rate alone does not show the full strain.

Hills. On a climb, your displayed pace drops for the same effort, and it goes back up on the descent. Researchers adjust pace for slope for exactly this reason. On hills, run by effort (how the conversation feels, how your legs feel) and don't fixate on the number. On trails, the kilometer-effort tool tackles the same problem.

What you can do at your next workout

1. Decide your goal before you start: easy, race pace or a fast workout. The goal sets the pace, not the other way around.
2. On an easy run, use the talk test and note your average pace.
3. Take a recent result (a 10 km race, for example) and enter it in the pace calculator to get your target paces. For a marathon, add margin.
4. In heat or on hills, run by effort and accept a slower pace without judging yourself.
5. Compare over a few weeks: if your easy pace drops at the same heart rate, that is a good sign.

This is the kind of reading KILYO does for you: it reads your workouts from your watch, analyzes your pace, heart rate, volume and consistency, and adjusts your training plan accordingly. To go further, read our guide to preparing for a 10K in 8 weeks.

Written with the help of AI.