Threshold Running
What is it?
Threshold running means running at your lactate threshold pace — the fastest pace you could sustain for around 45–60 minutes if racing. It's often described as "comfortably hard": fast enough that conversation is difficult, but controlled enough that you're not gasping.
You might also hear this called tempo running. Coaches sometimes draw a distinction between the two, but for most runners the terms are used interchangeably to mean sustained running at threshold effort.
How it works
As you run faster, your muscles produce lactate faster than your body can clear it, and it starts to build up in your bloodstream. Your lactate threshold is the point where this balance tips — beyond it, lactate accumulates rapidly and fatigue sets in quickly.
Training at or just around this pace teaches your body to:
- Clear lactate more efficiently
- Delay the point at which lactate starts to build up
- Sustain faster paces for longer before fatigue kicks in
Unlike VO2max intervals, threshold sessions use jogged recovery rather than standing rest. This is deliberate — it trains your body to keep clearing lactate while still moving, which is exactly what happens in a race.
Why it matters
Threshold pace sits right at the edge of "sustainable effort," which makes it one of the most race-relevant paces to train. Improving your threshold pace has a direct, physiological payoff: you can hold a faster pace for longer before you fatigue, across everything from 5K to marathon distance.
It's also a lower-risk session than all-out interval work. Because the effort is controlled rather than maximal, it's easier to hold form, easier to recover from, and can be done consistently — often weekly — throughout a training block.
Our Threshold Running Series
Rather than a single one-off session, we coach threshold running as a progressive 10-week series, based on an outline from Sage Canaday (a student of Lydiard and Daniels). Each week builds on the last — either by adding reps, extending the length of each effort, or reducing recovery — so your body is gradually asked to hold threshold effort for longer, with less rest, as the weeks go on.
The series is designed to be done once a week, and can be started at any point in a training cycle. Once you complete all 10 weeks, we recommend running a fresh 5K or 10K time trial — your threshold pace will likely have improved, and your training paces should be recalculated to match (see the VDOT calculator for this).
Warm-up: every session starts with at least a mile of easy running, ideally with some drills. Recovery: unlike VO2max sessions, recovery between reps should be jogged, not walked or stood — this trains your body to keep clearing lactate while still moving. Cool-down: finish every session with an easy jog.
| Week | Main activity | Time @ threshold (rest) | Work/Rest ratio |
|---|---|---|---|
| 1 | 2 x 10 min @ threshold, 2 min recovery | 20 min (2) | 5:1 |
| 2 | 20 min @ threshold (continuous) | 20 min (0) | – |
| 3 | 2 x 12 min @ threshold, 2 min recovery | 24 min (2) | 6:1 |
| 4 | 3 x 10 min @ threshold, 2 min recovery | 30 min (4) | 5:1 |
| 5 | 2 x 15 min @ threshold, 3 min recovery | 30 min (3) | 5:1 |
| 6 | 3 x 12 min @ threshold, 2 min recovery | 36 min (4) | 6:1 |
| 7 | 4 x 10 min @ threshold, 2 min recovery | 40 min (6) | 5:1 |
| 8 | 2 x 20 min @ threshold, 5 min recovery | 40 min (5) | 4:1 |
| 9 | 3 x 15 min @ threshold, 3 min recovery | 45 min (6) | 5:1 |
| 10 | 40–45 min @ threshold (continuous) | 40–45 min | – |
Notice weeks 2 and 10 are run as one continuous effort with no breaks at all — these bookend the series, and are a good marker of progress: the same "just threshold, no stopping" format, but nearly double the duration by the end.
Any individual week's session can also be used as a standalone threshold workout within another training plan — you don't need to be mid-series to use them.
How to pace it
To find your threshold pace, enter a recent race result into our training paces calculator and look at the Threshold pace on the Training tab. Without a calculator, a rough guide is 15–20 seconds per mile slower than your current 10K race pace, or the pace you could hold in a race for about an hour.
Effort-wise, it should feel steady and controlled throughout each rep — if you're fading significantly by the final rep or interval, the pace was too fast.
Coaching tip
The jogged recovery is easy to shortcut, especially in the longer, later weeks of the series — but it's doing real work. Standing or walking during recovery lets lactate clear passively; jogging forces your body to clear it while it's still moving, which is exactly what you need to be able to do in a race. Resist the temptation to stop moving between reps, even when it's tempting in weeks 7–9.
Related sessions
Threshold running is one piece of a balanced training week. Explore the other effort types:
- Hill Running — a lower-impact way to build strength and power
- Interval Running — shorter, harder efforts that raise your aerobic ceiling
- Easy Running — the foundation that makes every harder session possible
Want your threshold paces calculated for you? Try our Training Paces Calculator.