Interval training is essential if you want to improve as a runner. It’s one of the fundamentals of training for both amateur and elite runners. In this guide, you’ll learn what interval training is, what pace to run it at, how to structure a session and which workouts to choose for your level and the distance you’re training for.
The short answer
- Interval training alternates fast running with recovery periods, which lets you spend more time at a high pace than you could running continuously.
- There are short intervals (around your MAS), long intervals (10K pace or threshold) and race-specific pace work.
- A session always includes a warm-up, the main set and a cool-down.
- One interval session a week is enough for most runners; the rest of your training should mostly be easy running.
Contents
- What is interval training?
- Why do interval training?
- Short intervals or long intervals: what’s the difference?
- What pace should you run your intervals at?
- How is an interval session structured?
- Example workouts by level and distance
- What kind of session can I do?
- How many interval sessions per week?
- What pace should you run during the recovery?
- Frequently asked questions about interval training
- Sources
What is interval training?
Unlike a run at a steady pace, interval training alternates fast running with recovery periods.
One of the best-known interval sessions in France is the 30/30: 30 seconds fast followed by 30 seconds of recovery. You might repeat it 10 times, for example, which gives a 10 × (30″-30″) session. The block lasts 10 minutes in total: 5 minutes fast and 5 minutes of recovery.
When you start, you won’t necessarily feel comfortable at fast paces. But as with any training, the more you do, the more comfortable you become.
Why do interval training?
A continuous fast effort is tiring and takes time to recover from. By breaking it up, you recover more easily.
Above all, you can run longer at a given pace if you alternate running at that pace with recovery periods. In the well-known MAS sessions (short intervals), you can for example run 10 × 400 m with 1 minute of recovery between each 400 m, adding up to more than 10 minutes at high intensity. Running continuously, you could only run at your MAS for about 6 minutes.
Interval sessions improve your physiological capacities (heart, lungs, muscles…) and your mental strength. Running faster than on your easy runs also improves the efficiency of your stride.
Short intervals or long intervals: what’s the difference?
The term “interval training” covers very different sessions. They’re mainly classified by the length of the repetitions and the target pace:
- Short intervals: repetitions lasting from a few tens of seconds to 2 or 3 minutes, close to your MAS (maximal aerobic speed, also called vVO2max). Examples: 10 × (30″-30″), 10 × 400 m. They develop your MAS and VO2max.
- Long intervals: repetitions of roughly 3 to 10 minutes, at 10K pace or at your anaerobic threshold. Examples: 6 × 1000 m, 3 × 10′. They teach you to hold a strong pace for longer.
- Race-specific pace work: blocks at the pace of your goal race (half marathon, marathon…). We explain everything in our article on race-specific pace sessions.
What pace should you run your intervals at?
You can work on any pace with intervals, from sprinting to ultra-marathon. Sprinters might run 6 × 80 m with 5 minutes of recovery between each 80 m. Marathon runners might do 3 × 20 minutes with 5 minutes of recovery. As a rule, the shorter and faster the repetition, the longer the recovery.
Depending on the distance you’re training for, you’ll work at different interval paces. With a few variations, the pace is close to the race pace you’re preparing for. To find your paces, start by calculating your MAS, then use our MAS table to find the time to aim for over each distance. Our article on training paces also explains how to adjust them.
In any case, adjust your pace so you can finish the session without ending up in agony or flat on the ground 😉 Starting too fast is one of the most common mistakes in vVO2max workouts.
How is an interval session structured?
Before starting your interval session, always warm up with 15 to 30 minutes of easy running. Then, depending on the intensity of the session, do a few running drills to finish warming up your muscles. Finally, do 2 or 3 strides at session pace for about fifteen seconds to make sure you start at the right tempo.
The session can begin! You’ll get to know yourself as you go. Try not to start the first repetitions too fast. Halfway through, it starts to get hard and you need to hang on: you’re working on both your body and your mind. At the end of the session, you’ll be proud of what you’ve achieved!
Almost done: after the session, finish with 5 to 10 minutes of slow jogging to help you recover.
Example workouts by level and distance
Here are some example sessions for a runner who already trains regularly, at least 3 times a week. They’re guidelines: adjust the number of repetitions to your level and how you feel on the day.
| Goal | Example session | Find out more |
|---|---|---|
| Discover interval training | Fartlek: 8 × (1′ fast + 1′ easy) on a trail or in a park | Fartlek |
| Develop your MAS | 10 × (30″-30″) or 8 × 400 m, 1′ recovery | vVO2max workouts |
| 10K | 6 × 1000 m at 10K pace, 1′30″ recovery | Best 10K workouts |
| Half marathon | 3 × 10′ at threshold, 3′ jog recovery | Running at the anaerobic threshold |
| Marathon | Yasso 10 × 800 m or blocks at marathon pace | The Yasso 800 session |
| Trail | 10 × 1′ uphill, recover by jogging back down | 3 key hill workouts |
If you’re training for a race, the simplest option is to follow a plan that puts these sessions in the right order: 10K plan, half marathon plan, marathon plan or trail plan.
What kind of session can I do?
You can do intervals on the track or out in nature, whichever you prefer. To start with, choose flat routes. If you’re preparing for races with some elevation, you can then do an occasional session on hilly terrain or some hill repeats.
Fartlek is a type of interval session invented by the Swedes; the word means “speed play”. These sessions were designed to play with the terrain, for example by speeding up on hills. For your first interval sessions, you can challenge yourself to speed up until the next bridge or a particular tree.
If you’re training for a race, following a training plan with interval sessions is the ideal way to reach your goal. The sessions in the plan will be adapted to your experience and level. Just be careful not to overdo it, and make sure you recover well between sessions.
How many interval sessions per week?
For most runners, one interval session a week is enough. Experienced runners who train 4 to 5 times a week can do two, spaced at least 48 hours apart. The rest of your training should be at an easy pace: among high-level endurance athletes, about 80% of sessions are done at low intensity (Seiler, 2010). Easy endurance running remains the foundation of your progress, and intervals come on top of it.
To find out how many runs to plan in total, read our article on how often to run each week to progress.
What pace should you run during the recovery?
If you’ve been running for a few years, it’s better to jog during the recovery periods so that your heart rate doesn’t drop too much between repetitions. Beginners can walk. In MAS sessions, if the recovery is too long or too slow, you spend less time close to your maximum heart rate: you can then jog a little faster or shorten the recovery.
Active or passive recovery, duration, special cases: we’ve written a full article on recovery during interval training.
If you want to add intervals to your race preparation, the RunMotion Coach app is the companion you need! The RunMotion digital coach tells you what each session involves, with the corresponding paces, based on your level and preferences. You’ll find advice throughout your preparation and the motivation to improve 😉
Frequently asked questions about interval training
When should beginners start interval training?
Start by building a base of easy running: once you’ve been running regularly 2 to 3 times a week for a few weeks and can run 30 to 40 minutes continuously, you can introduce a simple interval session, such as a fartlek or a 30/30 with only a few repetitions.
How long does an interval session last?
Count on between 45 minutes and 1h15 in total: 15 to 30 minutes of warm-up, 10 to 30 minutes of main set depending on the type of intervals, then 5 to 10 minutes of cool-down.
Can you do interval training every day?
No. Interval training is demanding and your body needs to recover to benefit from it. Stacking hard sessions increases fatigue and the risk of injury without making you progress any faster.
Is it better to do intervals on the track or on the road?
The track lets you control distances and paces precisely, which is handy for short intervals. Roads and trails work very well for long intervals or fartlek, especially with a GPS watch. The most important thing is to choose a flat, safe route.
Sources
- Seiler S. What is best practice for training intensity and duration distribution in endurance athletes? Int J Sports Physiol Perform, 2010;5(3):276-291. DOI: 10.1123/ijspp.5.3.276
