Going off too fast
On the first reps, 100% of your vVO₂max feels slow, so you speed up. The end of the set makes you pay for it. The right speed is the one you can repeat identically over all 20 reps.
RunningVO2maxBeginner 47 min
30/30 running intervals (2 × 10)
30/30 running intervals: two sets of 10 × 30 seconds at 100% of your vVO₂max, with 30 seconds of jogging between reps. 10 minutes at that speed in a 47-minute session, in efforts short enough to start intervals without going into the red.
Session profile42 blocks
At a glance
- Duration
- 47 min
- Main target
- 100%vVO₂max5 Z5 · VO₂max
- Time at target
- 10 min
- Estimated load
- 46
- Structure
- 2 × (10 × 30″ at 100% vVO₂max, 30″ recovery), 3′ between sets
- Level
- Beginner
- Equipment
- GPS watch · Track (optional)
The session in detail
vVO₂max
Time in zone
- Z132 min
- Z25 min
- Z510 min
What the targets mean
| Target | Zone | Time | vVO₂max 14 km/h | vVO₂max 16 km/h | vVO₂max 18 km/h |
|---|---|---|---|---|---|
| 100% | 5VO₂max | 10 min | 4:17/km 117 m per rep | 3:45/km 133 m per rep | 3:20/km 150 m per rep |
| 50% | 1Recovery | 9 min | 8:34/km 58 m per rep | 7:30/km 67 m per rep | 6:40/km 75 m per rep |
| 25–35% | 1Recovery | 3 min | 17:09/km–12:15/km 175–245 m per rep | 15:00/km–10:43/km 200–280 m per rep | 13:20/km–9:31/km 225–315 m per rep |
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What this session is for
The 30/30 works your vVO₂max, the speed at which you reach your maximal oxygen uptake, also called maximal aerobic speed. It all comes down to the sequence: 30 seconds is too short to put you in the red, and 30 seconds of jogging doesn't let your breathing settle completely. Rep after rep, you spend longer close to VO₂max than in a single fast continuous run: that is what Billat's study, published in 2000, measured. The long-term effect of the 30/30 on its own is less well documented.
Who it's for
Runners new to intervals at vVO₂max: the efforts are short, the recoveries are jogged, and the pace stays the same from start to finish. More experienced runners get a short, sharp session that fits into a busy week. Either way, you need a recently tested vVO₂max, from a VAMEVAL test or a half-Cooper for example.
When to do it
One vVO₂max session a week is usually enough, and the 30/30 can be that session. Put it after an easy day or a rest day, never the day before a long run, another hard session or a race. Over a 4- to 6-week block, change one thing at a time: volume first, then intensity. Once 3 × 10 feels under control, move on to longer reps.
How to do it
Warm-up
15 min10′ at 60–65% vVO₂max + 5′ at 66–72% vVO₂max
10 minutes of easy running, then 5 minutes a little brisker, at a pace where you can still talk. Arrive at the first rep properly warm: 30 seconds at full speed on cold legs costs you the first few reps.
Main set
22 min2 × (10 × 30″ at 100% vVO₂max, 30″ recovery), 3′ between sets
Two sets of 10 × 30 seconds at 100% of your vVO₂max, each followed by 30 seconds of jogging, with 3 minutes of walking between the sets. Run every rep at the same speed, from the 1st to the 20th. On a track, distance is the most reliable guide: at 16 km/h, 133 metres in 30 seconds, a third of a lap. Genuinely jog the recoveries, don't walk: that jog is what keeps your breathing high. Only the break between sets is walked.
Cool-down
10 min10′ at 55–65% vVO₂max
10 minutes of very easy running. If you had to let the pace go before the end of the first set, make a note: it is a sign your vVO₂max is set too high.
How it should feel
The first reps feel easy: that's the trap. Around the sixth, your breathing takes off and the 30-second jogs seem to shrink. You finish each set short of breath, without ever having sprinted. Guide: 7 to 8 out of 10.
Common mistakes
Walking the recoveries
The 30 seconds between reps are jogged, at about half your vVO₂max speed. Walking lets your breathing drop too far and turns the session into a string of isolated sprints.
Training off an inflated reference
If you can't hold the pace before the end of the first set, it isn't a lack of willpower: your reference speed is probably too high. Retest, or lower it.
Running on a slope
Without a track, pick a flat stretch: a slight gradient is enough to throw your pace off and make the distances meaningless.
When to skip it
Before you start
- A recently tested vVO₂max: every pace depends on it.
- Being able to run 15 minutes easy without difficulty.
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.
- You are coming back from a long break: rebuild a few weeks of easy running first.
Origin and evidence
Level of evidence
Moderate evidenceLevel 3 of 5
The 30/30 at 100% / 50% of vVO₂max was studied by Billat et al. (Eur J Appl Physiol 2000;81(3):188-196). In runners with an average vVO₂max of 18.5 km/h, it gave about 7 min 51 s at VO₂max over 19 reps on average, against 2 min 42 s for a continuous run between threshold and vVO₂max. Other studies add nuance: Millet et al. (2003, 8 triathletes) measured much less time above 90% of VO₂max in 30/30 than in 60/30 (149 s against 531 s); Fleckenstein et al. (2024, 12 highly trained middle-distance runners) found intensified short intervals less effective than 4 × 3 min at 95% on that measure. Rozenek et al. (2007) compared 15/15, 30/15 and 60/15: the share of VO₂max reached rises with effort duration (71.6%, 84.6%, 89.2%). Some coaching sheets prescribe 105–110% for efforts of 15 to 30 seconds, such as one from the Normandy football league; the version Billat studied stays at 100%. The 2 × 10 split, the 3-minute break, the warm-up and the cool-down are Wattson choices. Bottom line: the immediate effect is well documented, the evidence for long-term gains from the 30/30 alone is weaker.
Sources
- Billat V. L. et al., Eur J Appl Physiol 2000;81(3):188-196
- Millet G. P. et al., Can J Appl Physiol 2003
- Rozenek R. et al., J Strength Cond Res 2007
- Fleckenstein D. et al., Front Sports Act Living 2024
- Ligue de football de Normandie (FFF), fiche « Bases VMA » ↗
Frequently asked questions
How fast should you run a 30/30?
At 100% of your vVO₂max: no faster, no slower. At 14 km/h that is 4:17/km, or 117 metres in 30 seconds; at 16 km/h, 3:45/km and 133 metres; at 18 km/h, 3:20/km and 150 metres. Some coaching sheets suggest 105–110%: the version Billat studied sits at 100%, with jogged recoveries at 50%.
Should you jog or walk the recoveries?
Jog, at about half your vVO₂max speed: 58 metres in 30 seconds at 14 km/h. That jog keeps your breathing from settling completely, and it is what makes the 30/30 work. Only the 3-minute break between the two sets is walked.
How many 30/30 reps for a first session?
Two sets of 10, so 20 reps and 10 minutes at vVO₂max, if you already have a few weeks of regular easy running behind you. If that is too much, start with shorter sets; once 2 × 10 feels comfortable, add a third set before touching the pace.
30/30 or 15/15: which one?
The 30/30 is easier to pace when you start: 30 seconds gives you time to feel the speed. The 15/15 is choppier and asks you to keep the recovery brisk. Both target vVO₂max, and they work well together across a block.
How long at VO2max does a 30/30 give you?
In Billat et al. (2000), runners with an average vVO₂max of 18.5 km/h spent about 7 min 51 s at VO₂max over an average of 19 reps, against 2 min 42 s in a continuous run. Other studies measured less, and time near VO₂max varies a lot from one runner to another.
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