Lactate Shuttle: a workout to learn how to use lactate
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What is Lactate Shuttle training?
Lactate Shuttle training alternates periods of running at a high intensity, close to LT2, with periods at a more moderate pace, around LT1.
The aim is to vary lactate production and use within a single workout. Lactate production increases during the faster segments. During the slower segments, you keep running rather than taking a full recovery, and your body continues to use some of the lactate produced during the previous segment.
This workout can be useful when preparing for endurance events, especially the marathon, because it trains changes in intensity while maintaining a substantial amount of continuous running.
Why use Lactate Shuttle training for running?
Lactate is not simply a waste product produced by muscles during exercise. It can be transported to different tissues and used as an energy source or contribute indirectly to glucose production.
Lactate Shuttle training therefore alternates a phase in which lactate production is high with a lower-intensity phase, without stopping completely.
The LT1 segment has two roles: it allows you to keep running at a relatively high intensity while giving your body an opportunity to process lactate produced during the previous segment.
However, this workout should not be presented as a way to avoid “hitting the wall” in a marathon on its own. Marathon performance depends on many factors, including training level, endurance, race pace, glycogen management, nutrition and hydration, recovery, and experience over the distance.
How do you do a Lactate Shuttle workout?
The principle is simple: alternate a period at LT2 with a period at LT1, with no standing recovery between them.
A basic workout
A simple introductory workout is:
3 × (3 minutes at LT2 + 3 minutes at LT1)
There is no additional recovery between repetitions. The LT1 segment serves as active recovery after the LT2 segment.
A track or measured-course version
If you prefer to work with distances rather than time, you can do:
3 × (1 km at LT2 + 1 km at LT1)
This version gives you precise reference points on a track or measured course.
How can you progress the workout?
As with any demanding workout, increase the training load gradually. One step could be to build up to five repetitions before gradually increasing the total volume.
A more demanding workout could eventually be:
(5 or 6) × (3 minutes at LT2 + 3 minutes at LT1)
This is a substantial training load and should only be included in a plan appropriate to the runner’s level.
What pace should you run during a Lactate Shuttle workout?
The workout is based on two different intensities:
- LT1: the pace associated with the first lactate threshold. The intensity is moderate but high enough to keep running actively.
- LT2: the pace associated with the second lactate threshold. It is considerably faster and close to the intensity usually targeted in threshold workouts.
The percentages of maximal aerobic speed (MAS) and maximum heart rate shown below are only guidelines. Physiological thresholds vary from runner to runner and cannot be determined accurately from a simple percentage of MAS or maximum heart rate.
If you know your thresholds from a laboratory test or another reliable method, use those values rather than an estimate based solely on MAS.
To learn more about maximal aerobic speed (MAS), see the pages about testing and calculating training paces.
What if LT1 pace is difficult to maintain?
If you find it difficult to maintain LT1 pace throughout the workout, one option is to run the slower segment at a slightly easier pace.
Marathon pace can be a good alternative for runners preparing for that distance.
This turns the workout into a combination of alternating intensities and marathon-pace training.
The key is to preserve the principle of the workout: the slower segment should allow you to keep moving without stopping before starting the next LT2 segment.
Is Lactate Shuttle training useful for marathon preparation?
Lactate Shuttle training can have a place in a marathon plan, particularly as part of general preparation or a long run.
One potential benefit for marathon training is combining relatively intense segments with a substantial duration of continuous running. However, it does not replace other essential elements of preparation, including long runs, marathon-pace work, endurance development and recovery.
I have included this type of workout in my own training, including my preparation for the La Rochelle Marathon, where I improved my personal best.
That personal experience encouraged me to keep this workout in my training toolkit, but it cannot, by itself, establish a cause-and-effect relationship between Lactate Shuttle training and improved performance.
Speed and pace chart based on maximal aerobic speed (MAS)
The table below provides indicative values for planning the workout based on MAS.
Note: these values are estimates. Lactate thresholds depend heavily on each runner’s individual characteristics.
For example, at a MAS of 19 km/h, the table gives approximately 14.8 km/h for LT1, or about 4:03/km, and 16.2 km/h for LT22, or about 3:43/km.
If you do not know your MAS, you can estimate it using a Cooper test or a half-Cooper test.
| MAS (km/h) | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 |
|---|---|---|---|---|---|---|---|---|---|---|
| LT1 | 7.8 km/h | 8.6 km/h | 9.4 km/h | 10.1 km/h | 10.9 km/h | 11.7 km/h | 12.5 km/h | 13.3 km/h | 14 km/h | 14.8 km/h |
| LT2 | 8.5 km/h | 9.4 km/h | 10.2 km/h | 11.1 km/h | 11.9 km/h | 12.8 km/h | 13.6 km/h | 14.5 km/h | 15.3 km/h | 16.2 km/h |
| LT1 | 7:42 | 7:00 | 6:25 | 5:55 | 5:30 | 5:08 | 4:48 | 4:31 | 4:16 | 4:03 |
| LT2 | 7:04 | 6:25 | 5:53 | 5:26 | 5:03 | 4:42 | 4:25 | 4:09 | 3:55 | 3:43 |
Lactate Shuttle workout examples
Here are several ways to incorporate the Lactate Shuttle principle into your training:
- Beginner: 3 × (3 min at LT2 + 3 min at LT1)
- Standard workout: 4 × (3 min at LT2 + 3 min at LT1)
- Track workout: 5 × (1 km at LT2 + 1 km at LT1)
- Longer workout: (5 or 6) × (3 min at LT2 + 3 min at LT1), for runners already accustomed to this training load.
- Marathon preparation: consider replacing LT1 with marathon pace if LT1 is too difficult to maintain.
The workout must be appropriate for the runner’s ability and the overall weekly training load. Lactate Shuttle is demanding and should not automatically be added to an already heavy training programme.
Lactate Shuttle: do you need recovery between repetitions?
No, there is normally no standing recovery between repetitions.
The workout is built around alternating between the two intensities. The LT1 segment is the active recovery before returning to LT2.
This continuous effort is what distinguishes the workout from traditional intervals with full or partial recovery.
Lactate Shuttle training for the 10K and half-marathon
Alternating between two intensities can also be used when preparing for distances shorter than the marathon.
The training load and paces must be adapted to the goal. For a 10K or half-marathon, this workout can be included in a plan that also features race-pace work, endurance training and appropriately paced long runs.
As always, a workout’s value depends as much on how it fits into the overall training plan as on the session itself.
Frequently asked questions about Lactate Shuttle training
What is Lactate Shuttle training?
Lactate Shuttle is a training method that alternates high-intensity periods, usually around LT2, with lower-intensity periods around LT1, without stopping to recover.
How many repetitions should you do?
A typical workout could consist of 5 × (3 min at LT2 + 3 min at LT1). The number of repetitions should be adjusted to the runner’s ability and overall training load.
Can you do Lactate Shuttle training without knowing your lactate thresholds?
Yes. You can use estimated pace, MAS or heart-rate values, but these are only approximations. Knowing your thresholds makes it possible to tailor the workout more accurately.
Can you replace LT1 with marathon pace?
Yes, particularly during marathon preparation if LT1 pace is difficult to maintain. This adaptation also combines Lactate Shuttle training with marathon-pace work.
Can Lactate Shuttle training prevent hitting the wall?
It would be an overstatement to claim that this workout alone can prevent hitting the wall. It can be part of marathon preparation, but glycogen management, pacing, endurance, nutrition, hydration and overall training also play important roles.
How often should you do Lactate Shuttle training?
One session per week may be appropriate in a suitable training plan, but there is no universally correct frequency. Consider the runner’s level and the other quality sessions scheduled that week.
Take your training further
Lactate Shuttle is just one of many workouts that can help develop your running. To build a well-rounded training plan, you can also explore:
- Maximal aerobic speed (MAS) and how to assess it
- Calculate your interval training times
- Long runs and endurance training
- Understanding LT1
- Understanding LT2
To develop your running ability, vary the distances and durations of your efforts. To calculate target times for different distances based on your MAS, visit the interval training calculator.