If you follow running news, you’ve probably seen the Norwegian 4×4 workout everywhere lately. This high-intensity protocol, developed by Norwegian researchers decades ago, has become one of the big trends in 2025 thanks to its ability to improve VO2 max, cardiovascular health and endurance in less time than traditional steady-state runs.
In this guide, you’ll find exactly what the Norwegian 4×4 workout is, what recent science says, how to adapt it to your current level without getting hurt and how to integrate it into your plans using tools like SnapRace.
What the Norwegian 4×4 workout is and where it comes from
The Norwegian 4×4 workout is a HIIT protocol for endurance athletes built around four long intervals at high intensity. It was created in the 1990s at the Norwegian University of Science and Technology, where exercise physiologists were looking for a simple but very effective way to boost aerobic capacity in endurance sports.
The basic structure is always the same:
- Warm-up: 8–10 minutes of easy jogging or light cardio.
- 4 work intervals: 4 minutes each at 85–95% of your maximum heart rate (around 8–9 out of 10 on a perceived exertion scale).
- Active recovery: 3 minutes of very easy jog or brisk walk between intervals, roughly at 65–70% of max heart rate.
- Cool-down: 5–10 minutes very easy + light mobility or stretching.
In total, the full session usually takes 35–40 minutes, but your heart spends a significant amount of time working close to its full capacity. That’s a big part of why the Norwegian 4×4 is so effective for VO2 max and cardiovascular health.
Compared with classic HIIT sessions built on very short intervals (20–30 seconds), the Norwegian 4×4 workout uses longer work blocks that allow your heart to reach and maintain a high output for several minutes. For distance runners, that’s exactly the type of stimulus that transfers well to race performance.
Benefits of the Norwegian 4×4 for runners: more VO2 max, more endurance, less time
The studies that helped popularize the Norwegian 4×4 protocol show clear benefits for both sedentary adults and trained endurance athletes. For everyday runners, the key points are:
- Significant VO2 max improvements: VO2 max is the maximum amount of oxygen your body can use during intense exercise. The higher it is, the faster you can run at the same effort. Training plans including at least one 4×4 session per week over several months have shown noticeable gains in this metric.
- A stronger, “younger” heart: research in middle-aged adults shows that this kind of training can reduce cardiac stiffness and improve arterial function, both important markers for cardiovascular risk.
- Better ability to hold race pace: spending more time in high heart-rate zones teaches your body to tolerate 10K, half-marathon and even marathon pace for longer.
- Highly time-efficient: if you are short on time, one well-executed Norwegian 4×4 workout can provide more cardiometabolic stimulus than a longer easy run.
- Direct transfer to distance racing: the protocol is particularly useful for marathoners, half-marathoners and triathletes, but also works well when targeting a 5K or 10K personal best.
It’s important to stress that the Norwegian 4×4 is not a magic bullet. It works best as a complement to your easy runs, long runs and a solid strength training routine for runners.
Risks and common mistakes with the Norwegian 4×4 method
Just because the Norwegian 4×4 workout is trending doesn’t mean it’s right for everyone, or that you should do it at any cost. These are some of the most common pitfalls:
- Starting too hard: if you’ve never done HIIT before, jumping straight into 4×4 minutes at 90–95% max heart rate is likely to end in excessive fatigue or niggles.
- Confusing “hard” with “all out”: the intervals should feel like an 8–9 out of 10. If you sprint from the first minute, you won’t be able to finish the set at a consistent pace.
- Doing it too often: for most recreational runners, one 4×4 workout per week is plenty. At most, two during specific blocks and only if you have a solid base.
- Ignoring life stress: if you’re coming off a very demanding week at work, have slept poorly or are feeling run down, it may be smarter to swap the 4×4 for an easier session.
- Skipping medical clearance: if you have cardiovascular risk factors or any doubts about your heart health, talk to your doctor before adding high-intensity intervals like this.
If you’re a beginner, it’s usually better to start with shorter intervals or a run–walk approach and spend a few months building your aerobic base before tackling the full Norwegian 4×4 workout.
How to do your first Norwegian 4×4 running workout (step by step)
The session below is designed for runners who can comfortably complete 40–50 minutes of continuous running and have already finished at least one 10K.
- Warm-up (10 minutes)
5 minutes of very easy jog + 5 minutes gradually picking up the pace towards your regular easy run pace. Add 2–3 short 15-second strides if you’re used to them. - Interval 1 – 4 minutes
Run at a pace that feels hard but sustainable for the full 4 minutes. You should only be able to say a few words at a time. - Recovery 1 – 3 minutes
Drop to an easy jog or brisk walk. Your breathing should calm down progressively. - Intervals 2, 3 and 4
Repeat the same 4 minutes strong + 3 minutes very easy structure. If your last interval is much slower than the first, you probably went out too hard. - Cool-down (5–10 minutes)
Very easy jog or walking + light mobility or stretching.
If you don’t use a heart rate monitor, rely on perceived exertion: aim for 8–9/10 on the intervals and 2–3/10 during recovery.
How to fit the Norwegian 4×4 into your training week
If you’re training for your first 10K
Here, the Norwegian 4×4 should only come in after you’ve built a basic foundation of several weeks running 3 times per week for at least 40 minutes without stopping.
- Recommended frequency: 1 Norwegian 4×4 every 10–14 days.
- Example week:
- Monday: off or light strength.
- Wednesday: 40′ easy run.
- Friday: Norwegian 4×4 workout.
- Sunday: 50–60′ long easy run.
If you’re chasing a 10K or half-marathon PB
For more experienced runners (several 10Ks behind you and 3–4 days of training per week), the Norwegian 4×4 workout can be one of your two weekly quality sessions.
- Recommended frequency: 1 session per week.
- Sample week:
- Monday: strength + running drills.
- Tuesday: 45′ easy run.
- Thursday: Norwegian 4×4.
- Saturday: 70–90′ long run with a light progression at the end.
If you’re an advanced marathoner
In marathon build-ups with higher mileage, the 4×4 is often used in specific phases to boost VO2 max without relying solely on very short track intervals.
- Recommended frequency: 1 weekly session, at most 2 in very targeted microcycles, always scheduled away from your long run.
- Best paired with: tempo runs, long runs with marathon-pace blocks and a solid strength routine.
Example Norwegian 4×4 week for a sub-50′ 10K goal
Let’s say you run 35–45 km per week and want to break 50 minutes in the 10K. A mid-plan week could look like this:
- Monday: 30′ very easy run + 20′ strength (legs and core).
- Tuesday: rest or light walking.
- Wednesday: 10′ warm-up + 4×4′ slightly faster than 10K pace (3′ very easy jog between intervals) + 10′ cool-down.
- Friday: 45′ continuous easy run at conversational pace.
- Sunday: 75′ long easy run, with the last 15′ a touch faster.
On heavy or stressful weeks, you can swap the 4×4 for a steady run with a few short pickups. The goal is for the Norwegian 4×4 workout to add to your training, not to leave you wiped out for days.
Using SnapRace to put the Norwegian 4×4 into practice
One of the tricky parts of the Norwegian 4×4 workout is nailing the timing, pace and intensity while running outdoors. That’s where tools like SnapRace can help you train smarter with less stress.
- Design interval-friendly routes: with SnapRace you can create routes with few turns and gentle elevation so your 4-minute intervals are as steady as possible.
- Turn-by-turn guidance: if you tend to get lost, turn-by-turn navigation means you don’t have to stare at a map mid-interval and can focus fully on the effort.
- Track your progress: save your 4×4 workouts and review how your average interval pace and perceived effort evolve over several weeks.
- Combine different stimuli: alternate 4×4 routes with easy runs and long runs to build a varied and motivating training week.
If you want to dive deeper into running science, check out our article on running economy and how to improve your efficiency, where you’ll see how intervals, strength training and technique all fit together.
The Norwegian 4×4 is a powerful tool, not a magic trick. Add it on top of a solid base, smart planning and good recovery habits, and it can become one of your best allies to take your running to the next level.