Running the blocks too fast
Five-minute blocks invite you to speed up: that's no longer threshold, it's long vVO₂max reps. Threshold pace, 87–91% of vVO₂max, is roughly what you'd hold for an hour in a race: comfortably hard, never flat out.
RunningThresholdBeginner 60 min
Cruise intervals for runners (6 × 5 min at threshold)
Cruise intervals for running: six 5-minute blocks at threshold pace, 87–91% of your vVO₂max, with 1 minute of walking between each. 30 minutes at threshold in an hour-long session, easier to hold than a continuous tempo run of the same length.
Session profile14 blocks
At a glance
- Duration
- 60 min
- Main target
- 87–91%vVO₂max4 Z4 · Threshold
- Time at target
- 30 min
- Estimated load
- 70
- Structure
- 6 × 5′ at 87–91% vVO₂max, 1′ recovery
- Level
- Beginner
- Equipment
- GPS watch
The session in detail
vVO₂max
Time in zone
- Z125 min
- Z25 min
- Z430 min
What the targets mean
| Target | Zone | Time | vVO₂max 14 km/h | vVO₂max 16 km/h | vVO₂max 18 km/h |
|---|---|---|---|---|---|
| 87–91% | 4Threshold | 30 min | 4:56/km–4:43/km 1015–1062 m per rep | 4:19/km–4:07/km 1160–1213 m per rep | 3:50/km–3:40/km 1305–1365 m per rep |
| 25–35% | 1Recovery | 5 min | 17:09/km–12:15/km 58–82 m per rep | 15:00/km–10:43/km 67–93 m per rep | 13:20/km–9:31/km 75–105 m per rep |
Put this session on your watch
Wattson works out your paces and sends the session to your Garmin, Wahoo, Coros or Suunto.
What this session is for
Like a tempo run, cruise intervals push up the pace you can hold for a long time, your threshold pace. The difference is in how it's sliced: by cutting 30 minutes at threshold into six blocks, you rack up more of it than you could continuously, with far less mental strain. The minute's break clears your head without letting you fully recover: your breathing and heart rate stay up from one block to the next.
It's Jack Daniels' idea: reps at T pace, his threshold pace, with a work-to-rest ratio of about 5 to 1. According to a secondary summary of his book, the format lets anyone who can hold 20 minutes continuously build up at least 30 minutes at threshold.
Who it's for
Runners from 10K to marathon, including those who can't yet hold 20 continuous minutes at threshold: that's exactly who the format is for. You need a few weeks of regular easy running behind you, and a recently measured vVO₂max to set the pace. Once the blocks go well, the continuous tempo run is the logical next step.
When to do it
One threshold session a week is a common guideline: cruise intervals can alternate with a tempo run from week to week. Put it after an easy day or a rest day, never the day before a long run, another hard session or a race. To progress, lengthen the blocks, 4 × 10 minutes with 90 seconds' rest, then 3 × 2 miles with 2 minutes, before moving on to a continuous tempo run.
How to do it
Warm-up
15 min10′ at 60–65% vVO₂max + 5′ at 66–72% vVO₂max
10 minutes of easy running at 60–65% of vVO₂max, then 5 minutes at 66–72%. No need for strides: threshold pace isn't fast enough to call for them.
Main set
35 min6 × 5′ at 87–91% vVO₂max, 1′ recovery
Six 5-minute blocks at 87–91% of your vVO₂max, with 1 minute of walking between each. At 16 km/h that's 4:19 to 4:07/km, or 1,160 to 1,213 metres per block. The pace should stay the same from the first block to the sixth: if you can't hold it by the fourth, you went off too fast. Keep the break short: stretch it and the session turns into a string of separate runs.
Cool-down
10 min10′ at 55–65% vVO₂max
10 minutes of very easy running at 55–65% of vVO₂max. If the last block felt as easy as the first, you can move to 10-minute blocks next time.
How it should feel
A touch easier than a continuous tempo run, because you get a breather every 5 minutes. You should be able to say a few words, not hold a conversation. The last two blocks are the most demanding. A minute's walk is just long enough to check your watch, check it again, and set off. Guide: 6 to 7 out of 10 on each block.
Common mistakes
Stretching the break
The minute's walk is short on purpose: it keeps your breathing up and makes the session genuine threshold work. Take three minutes and you're running six separate blocks.
Raising the pace instead of lengthening
When the session gets easy, Daniels' progression is to lengthen the blocks, not to run faster. A quicker pace would take you off threshold.
Putting it the day before a long run
Thirty minutes at threshold leaves its mark. The day before a long run or a race, stick to easy running.
When to skip it
Before you start
- A few weeks of regular easy running.
- A recently measured vVO₂max.
Skip it if
- You have pain or a recent injury.
- A long run, another hard session or a race is planned for the next day.
Origin and evidence
Level of evidence
Established practice, no dedicated studyLevel 1 of 5
Jack Daniels (Daniels' Running Formula, Human Kinetics, several editions, consulted through extracts and reading notes) describes cruise intervals as reps at T pace, his threshold pace, with a work-to-rest ratio of about 5 to 1, by distance: 5 × 1 mile with 1 minute's rest, or 3 × 2 miles with 2 minutes. According to a secondary summary, the format lets anyone who can hold 20 minutes continuously accumulate at least 30 minutes at T pace. No dedicated study has been found. Threshold pace at 87–91% of vVO₂max, the time-based version (5-minute blocks, same ratio), walking instead of standing rest, the warm-up and the cool-down are Wattson choices. Bottom line: the practice of a respected coach, moderate confidence.
Sources
- Daniels J., Daniels' Running Formula, Human Kinetics
Frequently asked questions
What pace should cruise intervals be run at?
At threshold pace, 87–91% of your vVO₂max: 4:56 to 4:43/km at 14 km/h, 4:19 to 4:07/km at 16, 3:50 to 3:40/km at 18. It's Daniels' T pace, roughly what you'd hold for an hour in a race, the same as for a tempo run.
Cruise intervals or a tempo run: which should I choose?
Cruise intervals if you can't yet hold 20 continuous minutes at threshold, or if you want more time at that pace: 30 minutes instead of 20. A tempo run asks you to hold the pace without a break, closer to racing. You can alternate the two from week to week.
Walk or jog during the one-minute break?
Daniels prescribes a simple, very short rest; walking is a Wattson choice, to keep your legs moving. What matters is the length: one minute, no more, so your breathing stays up and the six blocks add up to a single piece of threshold work.
How do I progress with cruise intervals?
By lengthening the blocks at the same pace: 4 × 10 minutes with 90 seconds' rest, then 3 × 2 miles with 2 minutes, before moving to a continuous tempo run. If your vVO₂max improves, update it: your paces follow.
Related sessions
Take it up a level with Wattson
An intuitive workout editor to build cycling and running sessions in no time, then sync them to your watch or bike computer: Wahoo, Garmin, Suunto or Coros.
Try this session