Long intervals: 1,000 m, 2,000 m, 3,000 m… the session that builds your 10K and half
Long intervals are 3-to-8-minute repetitions between 88 and 95% of MAS with short recoveries. It's the most productive session for the 10K and half marathon. Paces, formats, progression across a plan, and how to send it to your watch.
Last updated: 2026-09-28
Your long intervals on the watch, in one sentence
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What are long intervals?
Long intervals are repetitions of 800 m to 3,000 m, i.e. 3 to 8 minutes of effort, run between 10K pace and 5K pace, that is 88 to 95% of MAS, with short recoveries of 1 to 3 minutes. Unlike short intervals (200 to 400 m at 100% of MAS and above), they don't chase raw speed but the ability to hold a high pace for a long time. It's the key session of 10K and half marathon plans.
Physiologically, the session works above threshold and close to VO2 max without reaching it: the heart runs between 90 and 95% of its maximum during the last repetitions. This zone most directly improves 10K time, and makes half-marathon pace feel comfortable.
Try it with your own Garmin
Free, nothing to install: connect your Garmin, then ask Claude or ChatGPT for your first workout. It lands on your watch within a minute.
At what pace and with what recovery?
| Repetition distance | % MAS | Cue | Recovery |
|---|---|---|---|
| 800 to 1,000 m | 92–95% | 5K pace | 1:30 to 2 min, jog |
| 1,200 to 1,600 m | 90–93% | Between 5K and 10K pace | 2 min, jog |
| 2,000 m | 88–91% | 10K pace | 2 to 3 min, jog |
| 3,000 m | 87–90% | 10K to threshold pace | 3 min, jog |
Recovery is jogged, never stood still: that's what keeps the heart high from one repetition to the next and makes the session worthwhile. Simple rule: recovery lasts between one third and one half of the effort time. If the last repetition is much slower than the first, the pace was too fast; aim for evenness, not a heroic first rep.
To know your exact paces, start from your MAS: the pace calculator gives your 10K and 5K paces to the second.
The five classic sessions
- 5 × 1,000 m at 5K pace, 2 min jog: the reference session, from 6 weeks of regular running.
- 6 × 1,000 m at 10K pace, 1:30: more volume, less intensity, ideal in the development phase.
- 3 × 2,000 m at 10K pace, 2:30: the specific 10K session par excellence.
- 2 × 3,000 m between 10K and threshold pace, 3 min: for the half marathon, it teaches you to hold on.
- Pyramid 1,000 – 2,000 – 3,000 – 2,000 – 1,000 m, faster on the way down: varied, demanding, once per block.
Every session starts with 15 to 20 minutes of progressive warm-up with a few strides, and ends with 10 minutes of cool-down. Count 50 to 70 minutes for the full session.
Progressing over 8 weeks
Progress first on the length of repetitions, then on their number, never both at once, and pace goes up last. Here is the outline of Running Workout's 10K plan, one long-interval session per week:
| Week | Session | Goal |
|---|---|---|
| 1–2 | 5 × 800 m then 5 × 1,000 m, 5K pace | Regain the feel for fast pace |
| 3–5 | 6 × 1,000 m, then 4 × 1,500 m, then 3 × 2,000 m | Lengthen without slowing |
| 6–7 | 3 × 2,000 m and 2 × 3,000 m at exact 10K pace | Lock in race pace |
| 8 | 4 × 1,000 m at 10K pace, long recovery | Taper: keep the speed, remove the fatigue |
One long-interval session a week is enough, two at most if it replaces the threshold session. The rest of the week stays easy: that's what lets you absorb the session.
Building the session on your Garmin watch
On Garmin Connect, the session is built in steps: warm-up by time, a "5 times" repeat holding the effort by distance with a pace target, then the recovery by time, and the cool-down. The watch beeps at each change and alerts you if you drift out of the target. It's tedious to enter by hand, especially to change the pace every week.
With Running Workout, one sentence to your assistant, Claude or ChatGPT, is enough: "Create 3 × 2,000 m at 10K pace with 2:30 jog for Thursday". It knows your MAS, computes the target, and the session appears on the watch with its steps. The following week, it lengthens it on its own if you follow a plan.
Create a long-interval session for Thursday: 20 min warm-up, 3 × 2,000 m at my 10K pace, 2:30 jog between, 10 min cool-down, and send it to my Garmin watch.Frequently asked questions
Short or long intervals: which to choose?
Both, at different times. Short (200 to 400 m at MAS) develops speed and running economy, useful early in a plan and for the 5K. Long (1,000 to 3,000 m) builds the ability to hold a high pace: that's what makes the 10K and half. A plan first alternates the two, then favors long intervals as the race approaches.
What heart rate during long intervals?
Between 88 and 95% of max HR at the end of a repetition. But the heart takes one to two minutes to rise: don't drive the session by heart rate, drive it by pace, and use heart rate afterwards to check the last repetitions didn't exceed 95%.
Can I do long intervals on a treadmill or uphill?
On a treadmill, yes, with 1% incline to make up for the lack of wind; the pace is even steadier. Uphill, it's no longer the same session: pace loses its meaning, you go by effort and time, and you work strength more than race pace.
How long before I see progress?
Three to four weekly sessions are enough to feel the difference on the third repetition, and six to eight weeks to see it on a 10K time. Progress comes provided the rest of the week stays easy.
Your long intervals on the watch, in one sentence
Connect your Garmin: your assistant computes the paces and sends the session, steps included.
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