WELLESLEYRUNNERS
Threshold Running
Running at your lactate threshold pace — the fastest pace you could sustain for 45–60 minutes if racing. “Comfortably hard”: conversation is difficult, but you're not gasping.
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 faster
Improve how efficiently your body removes lactate from the bloodstream during effort.
Delay the build-up
Push back the point at which lactate starts to accumulate rapidly in the first place.
Hold pace for longer
Sustain faster paces for longer before fatigue kicks in, across race distances.
Recover on the move
Unlike VO2max intervals, threshold sessions use jogged recovery rather than standing rest — training your body to clear lactate while still moving, exactly as it must 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.
The series can be started at any point in a training cycle, once a week. After 10 weeks, we recommend a fresh 5K or 10K time trial to recalculate your training paces.
| Wk | Main activity | Time @ threshold (rest) | Work/Rest |
|---|---|---|---|
| 1 | 2 × 10 min @ threshold, 2 min recovery | 20 min (2) | 5:1 |
| 2 | 20 min @ threshold (continuous) | 20 min (0) | — |
| 3 | 2 × 12 min @ threshold, 2 min recovery | 24 min (2) | 6:1 |
| 4 | 3 × 10 min @ threshold, 2 min recovery | 30 min (4) | 5:1 |
| 5 | 2 × 15 min @ threshold, 3 min recovery | 30 min (3) | 5:1 |
| 6 | 3 × 12 min @ threshold, 2 min recovery | 36 min (4) | 6:1 |
| 7 | 4 × 10 min @ threshold, 2 min recovery | 40 min (6) | 5:1 |
| 8 | 2 × 20 min @ threshold, 5 min recovery | 40 min (5) | 4:1 |
| 9 | 3 × 15 min @ threshold, 3 min recovery | 45 min (6) | 5:1 |
| 10 | 40–45 min @ threshold (continuous) | 40–45 min | — |
Warm-up
Every session starts with at least a mile of easy running, ideally with some drills.
Recovery
Jogged, not walked or stood — this trains your body to keep clearing lactate while still moving.
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, 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 in a race. Resist the temptation to stop moving between reps, even in weeks 7–9.
Related sessions
Threshold running is one piece of a balanced training week.
Ready to run threshold with us?
Threshold sessions run weekly and suit any runner training for a 5K through to a marathon. Get in touch and we'll help you find the right week to start.