Below you can read about interval training for runners. You can gain an insight into the basic idea behind interval training, when to make use of this type of training, as well as find a description of the different types of intervals. In this article, you can click on the different types to find concrete examples of training plans.
What is interval training?
Interval training is basically running training where you switch between different paces (running speeds). The basic idea of intervals is that you break up your run into shorter chunks, so that you can run further at a given pace than if you tried to do it in one go.
For example, imagine you run 1000 m intervals. If you run at 5 km pace (i.e. the pace you can maintain for 5 km in one go), then you could, for example, do 6-8 x 1000 m. This would be possible because you take a break between the 1000 m intervals (2-3 minutes), and overall you will have covered 6-8000 m at 5 km pace.
Why do interval training?
For the very reason that it becomes possible to run further at a given pace, you can achieve better results for different parameters by doing interval training. This type of training gives different results, dependent upon your choice of training plan, but generally speaking this is a form of training that can improve your performance considerably, and which, popularly speaking, is known for being able to "boost" your running form.
Why not just always do interval training?
Most commonly, interval training involves "high-intensity training", and so firstly it's incredibly important to emphasise that high-intensity training strains the body. The strain in itself is not problematic as such, but if the strain becomes too much, the result will not be as you had hoped for, and in the worst case can also leave you injured.
For this reason, it is important not to "overdose" on interval training, but instead seek to do as little as possible, but still get the benefit you want. If you run more intervals than you need, in principle you will just end up tiring yourself unnecessarily without added benefit.
It is difficult to suggest specific amounts for interval training, as training plans are dependent upon the individual runner and the context they find themselves in. But as a general rule of thumb, your limit ought to probably be around 15-20%. In other words, it is not recommended that more than 15-20% of your weekly training time consists of high-intensity intervals.
If you've never done interval training before, it won't take long for you to achieve good results. Therefore, it is adviseable to start by running half as many intervals (compared to the examples given below) and slowly work your way up.
Different results from different interval training plans
As mentioned, intervals are just a form of running training where you switch between different paces. Dependent upon the pace you run and how long your intervals and breaks are, you will place different demands on your body.
In this section you will find the most common types of interval training, and you can click on the individual types to read more.
If you are in doubt as to which type is most valuable for your situation, you can start by varying the interval type from time to time.
"Fartlek"
"Fartlek" is the most unstructured way to practise doing interval running.
This form of interval training was developed back in 1930 by the Swede Gösta Holmér, and is called Fartlek in Sweden. In English-speaking countries 'Fartlek' is also often used as a term.
In essence, fartlek consists of running training, where you increase and decrease the pace during the run. When you change pace, for example, between lampposts, when you meet a hill or some other points in the landscape. Some also do time-based fartlek, although this type tends to be more structured than speed play is otherwise usually done.
The result achieved by doing speed play is naturally rather difficult to say conclusively, as the individual form of fartlek a runner does will likely vary a lot. Therefore, the result may be similar to the results achieved by doing VO2 max intervals or even sprint intervals (read more about these types below).
VO2 max intervals
Result: Higher VO2 max (greater fitness level)
VO2 max intervals aim to improve your maximum oxygen uptake. Research is continually finding out about different ways to do so, but overall it seems that the most important factor in relation to VO2 max is the ability to transport as much oxygen as possible to the muscles.
The heart is a central factor here, which means that you will be expected to improve your fitness level if you train your heart to become larger and stronger.
A classic VO2 max training plan is:
- 5 x 3 minutes med 3 minutes walking break imellem.
If you have had a test done (and thus know your training zones), it can be worthwhile to aim for doing intervals between zone 4 and (possibly 5). Alternatively, you can either try to run the highest possible pace that you can maintain at all intervals, or stay above 90% of your maximum heart rate.
Find other examples of VO2 max intervals here
Lactate threshold intervals
Result: Longer running distance at competition speed
Lactate threshold intervals are intervals where you run at a lower intensity than when doing VO2 max intervals. This means that you run 'below the threshold', so to speak - i.e., at an intensity that is slightly lower than VT2 (if you have had a test done), which is also called the anaerobic threshold. In practice, this will typically be somewhere between 10 km and half marathon pace.
By being just below the threshold instead of above, you are able to get more minutes of running at a relatively high intensity than otherwise. If you would like to read more about the results of this form of training, then take a look at the article via the link just below. These training plans generally contain a high amount of running, so this type is not the obvious choice for beginner runners.
An example of a lactate threshold intervals training plan:
- 6 x 2000 m doing half marathon pace + 2 minutes jogging break
Find other examples of lactate threshold intervals here
Lactate tolerance intervals
Result: Greater lactate tolerance
When running lactate tolerance intervals, it takes place at a high speed – i.e. between ca. 800 - 1500 m pace (if you have an idea of how quick this is). If you don't know your pace in terms of distances, it can probably best be described as a pace where you run a form of 'controlled sprint' - that is, quite close to a full sprint!
The length of the intervals is long enough for you to produce a considerable amount of lactic acid, but on the other hand, the break is also long enough for you to more or less get rid of the lactic acid so you are ready for the next interval.
An example of a lactate tolerance intervals training plan:
- 10 x 200 m doing 800 m pace + 3 minutes walking break
Find other examples of lactate tolerance intervals here
Hill repeats
Result: Everything from improved running efficiency to higher VO2 max (fitness level) – depends on type of hill repeats training.
Hill repeats are done differently around the world. Overall, the advantage of hill repeats is that you can work your muscles at maximum capacity, without suffering such a shock impact as if you were to run at the same intensity on a flat road.
You can use different hills with different gradients, but try to avoid the overly steep hills unless you specifically need to train this type. A guideline is 5-10% gradient upwards.
As for the length of the intervals, hills are actually used for both relatively short sprints and longer intervals – i.e. anything from around 10 seconds to several minutes.
An example of a hill repeats training plan:
- 8-10 x 45 seconds + leisurely jog back to the start
Find other examples of hill repeats here
Sprint intervals
Result: Improved running efficiency and potential for speed
Sprint intervals are not only relevant for sprinters and middle distance runners. Long-distance runners can also greatly benefit from doing sprint training. There are several reasons for why, but one of them is that sprint training contributes to an improved running efficiency, which is a really important prerequisite for performing on long distances.
What is most important in is that the intervals take place at or close to top speed. That being said, of course, first and foremost, you need to be sensible.
If you haven't sprinted for a long time, it's better to start at a lower speed, so you're sure that your legs are also working after the session. From here you can gradually increase the pace, in order to finally be able to run at maximum speed on the sprints.
An example of a sprint interval training plan:
- 6 x 100 m at 95-100% top speed + 4-5 minutes break
Find other examples of sprint intervals here
